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Banker's algorithm

From Rosetta Code
Banker's algorithm is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.
This page uses content from Wikipedia. The original article was at Banker's algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)


The Banker's algorithm is a resource allocation and deadlock avoidance algorithm developed by Edsger Dijkstra that tests for safety by simulating the allocation of predetermined maximum possible amounts of all resources, and then makes a "s-state" check to test for possible deadlock conditions for all other pending activities, before deciding whether allocation should be allowed to continue.


Example input

Assuming that the system distinguishes between four types of resources, (A, B, C and D), the following is an example of how those resources could be distributed.

Note that this example shows the system at an instant before a new request for resources arrives.   Also, the types and number of resources are abstracted.   Real systems, for example, would deal with much larger quantities of each resource. 

Total resources in system:
A B C D
6 5 7 6

Available system resources are:
A B C D
3 1 1 2

Processes (currently allocated resources):
   A B C D
P1 1 2 2 1
P2 1 0 3 3
P3 1 2 1 0

Processes (maximum resources):
   A B C D
P1 3 3 2 2
P2 1 2 3 4
P3 1 3 5 0

Need= maximum resources - currently allocated resources
Processes (need resources):
   A B C D
P1 2 1 0 1
P2 0 2 0 1
P3 0 1 4 0



11l

Translation of: Python
TODO:

Translate all Spanish texts to English

V resources = Int(input(‘Cantidad de recursos: ’))
V processes = Int(input(‘Cantidad de procesos: ’))
V max_resources = input(‘Recursos máximos: ’).split_py().map(i -> Int(i))

print("\n-- recursos asignados para cada proceso  --")
V currently_allocated = (0 .< processes).map(j -> input(‘proceso #.: ’.format(j + 1)).split_py().map(i -> Int(i)))

print("\n--- recursos máximos para cada proceso  ---")
V max_need = (0 .< processes).map(j -> input(‘proceso #.: ’.format(j + 1)).split_py().map(i -> Int(i)))

V allocated = [0] * resources
L(i) 0 .< processes
   L(j) 0 .< resources
      allocated[j] += currently_allocated[i][j]
print("\nRecursos totales asignados  : #.".format(allocated))

V available = (0 .< resources).map(i -> :max_resources[i] - :allocated[i])
print("Recursos totales disponibles: #.\n".format(available))

V running = [1B] * processes
V count = processes
L count != 0
   V safe = 0B
   L(i) 0 .< processes
      I running[i]
         V executing = 1B
         L(j) 0 .< resources
            I max_need[i][j] - currently_allocated[i][j] > available[j]
               executing = 0B
               L.break
         I executing
            print(‘proceso #. ejecutándose’.format(i + 1))
            running[i] = 0B
            count--
            safe = 1B
            L(j) 0 .< resources
               available[j] += currently_allocated[i][j]
            L.break
   I !safe
      print(‘El proceso está en un estado inseguro.’)
      L.break

   print("El proceso está en un estado seguro.\nRecursos disponibles: #.\n".format(available))
Output:
Cantidad de recursos: 4
Cantidad de procesos: 3
Recursos máximos: 6 5 7 6

-- recursos asignados para cada proceso  --
proceso 1: 1 2 2 1
proceso 2: 1 0 3 3
proceso 3: 1 2 1 0

--- recursos máximos para cada proceso  ---
proceso 1: 3 3 2 2
proceso 2: 1 2 3 4
proceso 3: 1 3 5 0

Recursos totales asignados  : [3, 4, 6, 4]
Recursos totales disponibles: [3, 1, 1, 2]

proceso 1 ejecutándose
El proceso está en un estado seguro.
Recursos disponibles: [4, 3, 3, 3]

proceso 2 ejecutándose
El proceso está en un estado seguro.
Recursos disponibles: [5, 3, 6, 6]

proceso 3 ejecutándose
El proceso está en un estado seguro.
Recursos disponibles: [6, 5, 7, 6]

C

Standard binary heap-as-priority queue affair. Only that each node links back to its heap position for easier update.

There are two main() functions to choose from (look for #define BIG_EXAMPLE), one is for task example, the other is a much heavier duty test case. 

#include <stdio.h>
#include <stdbool.h>

int main() {
    int curr[5][5];
    int max_claim[5][5];
    int avl[5];
    int alloc[5] = {0, 0, 0, 0, 0};
    int max_res[5];
    int running[5];

    int i, j, exec, r, p;
    int count = 0;
    bool safe = false;

    printf("\nEnter the number of resources: ");
    scanf("%d", &r);

    printf("\nEnter the number of processes: ");
    scanf("%d", &p);
    for (i = 0; i < p; i++) {
        running[i] = 1;
        count++;
    }

    printf("\nEnter Claim Vector: ");
    for (i = 0; i < r; i++)
        scanf("%d", &max_res[i]);

    printf("\nEnter Allocated Resource Table: ");
    for (i = 0; i < p; i++) {
        for (j = 0; j < r; j++)
            scanf("%d", &curr[i][j]);
    }

    printf("\nEnter Maximum Claim table: ");
    for (i = 0; i < p; i++) {
        for (j = 0; j < r; j++)
            scanf("%d", &max_claim[i][j]);
    }

    printf("\nThe Claim Vector is: ");
    for (i = 0; i < r; i++)
        printf("%d ", max_res[i]);

    printf("\nThe Allocated Resource Table:\n");
    for (i = 0; i < p; i++) {
        for (j = 0; j < r; j++)
            printf("\t%d", curr[i][j]);
        printf("\n");
    }

    printf("\nThe Maximum Claim Table:\n");
    for (i = 0; i < p; i++) {
        for (j = 0; j < r; j++)
            printf("\t%d", max_claim[i][j]);
        printf("\n");
    }

    for (i = 0; i < p; i++)
        for (j = 0; j < r; j++)
            alloc[j] += curr[i][j];

    printf("\nAllocated resources: ");
    for (i = 0; i < r; i++)
        printf("%d ", alloc[i]);
    for (i = 0; i < r; i++)
        avl[i] = max_res[i] - alloc[i];

    printf("\nAvailable resources: ");
    for (i = 0; i < r; i++)
        printf("%d ", avl[i]);
    printf("\n");

    while (count != 0) {
        safe = false;
        for (i = 0; i < p; i++) {
            if (running[i]) {
                exec = 1;
                for (j = 0; j < r; j++) {
                    if (max_claim[i][j] - curr[i][j] > avl[j]) {
                        exec = 0;
                        break;
                    }
                }

                if (exec) {
                    printf("\nProcess%d is executing.\n", i + 1);
                    running[i] = 0;
                    count--;
                    safe = true;
                    for (j = 0; j < r; j++)
                        avl[j] += curr[i][j];
                    break;
                }
            }
        }

        if (!safe) {
            printf("\nThe processes are in unsafe state.");
            break;
        }

        if (safe)
            printf("\nThe process is in safe state.");

        printf("\nAvailable vector: ");
        for (i = 0; i < r; i++)
            printf("%d ", avl[i]);
    }

    return 0;
}
Input and Output:
Enter the number of resources: 4

Enter the number of processes: 5

Enter Claim Vector: 8 5 9 7

Enter Allocated Resource Table: 2 0 1 1 0 1 2 1 4 0 0 3 0 2 1 0 1 0 3 0

Enter Maximum Claim table: 3 2 1 4 0 2 5 2 5 1 0 5 1 5 3 0 3 0 3 3

The Claim Vector is: 8 5 9 7
The Allocated Resource Table:
        2       0       1       1
        0       1       2       1
        4       0       0       3
        0       2       1       0
        1       0       3       0

The Maximum Claim Table:
        3       2       1       4
        0       2       5       2
        5       1       0       5
        1       5       3       0
        3       0       3       3

Allocated resources: 7 3 7 5
Available resources: 1 2 2 2

Process3 is executing.

The process is in safe state.
Available vector: 5 2 2 5
Process1 is executing.

The process is in safe state.
Available vector: 7 2 3 6
Process2 is executing.

The process is in safe state.
Available vector: 7 3 5 7
Process4 is executing.

The process is in safe state.
Available vector: 7 5 6 7
Process5 is executing.

The process is in safe state.
Available vector: 8 5 9 7

FreeBASIC

Translation of: Kotlin
Dim As Integer i, j, r, p
Input "Enter the amount of resources: ", r
Input "Enter the number of processes: ", p

Print !"\nEnter the maximum resources: ";
Dim As Integer maxRes(r)
For i = 1 To r
    Input ; " ", maxRes(i)
Next i

Print !"\n\n-- resources allocated for each process --"
Dim As Integer curr(p, r)
For i = 1 To p
    Print "process"; i; ":";
    For j = 1 To r
        Input ; " ", curr(i, j)
    Next j
    Print
Next i

Print !"\n\n--- maximum resources for each process ---"
Dim As Integer maxReclam(p, r)
For i = 1 To p
    Print "process"; i; ":";
    For j = 1 To r
        Input ; " ", maxReclam(i, j)
    Next j
    Print
Next i

Dim As Integer recAsigad(r)
For i = 1 To p
    For j = 1 To r
        recAsigad(j) += curr(i, j)
    Next j
Next i
For i = 1 To r
    Print recAsigad(i); " ";
Next i

Dim As Integer recDispon(r)
Print !"\n\nTotal available resources: "; 'Available Resources
For i = 1 To r
    recDispon(i) = maxRes(i) - recAsigad(i)
    Print recDispon(i); " ";
Next i

Dim As Boolean executing(p)
For i = 1 To p
    executing(i) = True
Next i

Dim As Integer count = p
Do While count <> 0
    Dim As Boolean safe = False
    For i = 1 To p
        If executing(i) Then
            Dim As Boolean executes = True
            For j = 1 To r
                If (maxReclam(i,j) - curr(i,j) > recDispon(j)) Then
                    executes = False
                    Exit For
                End If
            Next j
            
            If executes Then
                Color 11 : Print !"\n\nprocess"; i; !" running."
                executing(i) = False
                count -= 1
                safe = True
                For j = 0 To r
                    recDispon(j) += curr(i,j)
                Next j
                Exit For
            End If
        End If
    Next i
    
    If Not safe Then
        Color 12 : Print !"\nThe processes are in an unsafe state."
        Color 7
        Exit Do
    End If
    
    Color 10: Print "The process is in a safe state."
    Color 7: Print "Available resources: ";
    For i = 1 To r
        Print recDispon(i); " ";
    Next i
Loop

Sleep

Go

WP cites EWD-108 and has EWD-623 as further reading. In using the analogy of a money, EWD-108 considers only a single type of resource. EWD-623 seems mostly in terms of a single resource but a couple of times says "all resources." This subtly hints that the algorithm can be adapted for multiple resource types. WP then gives an array-based presentation that works for multiple resources.

This solution is more inspired by EWD-623 than WP. EWD-623, while it talks of finding a permutation of processes, notes that the "ordering effort" can be stopped as soon as the process requesting resources happens to be found satisfiable. The solution here attempts to make this finding as soon as possible by moving the process to the front of a list of unsatisfied processes. Also since the solved permutation of satisfied processes has no use, it is not kept which simplifies the algorithm a bit. 

package bank

import (
    "bytes"
    "errors"
    "fmt"
    "log"
    "sort"
    "sync"
)

type PID string
type RID string
type RMap map[RID]int

// format RIDs in order
func (m RMap) String() string {
    rs := make([]string, len(m))
    i := 0
    for r := range m {
        rs[i] = string(r)
        i++
    }
    sort.Strings(rs)
    var b bytes.Buffer
    b.WriteString("{")
    for _, r := range rs {
        fmt.Fprintf(&b, "%q: %d, ", r, m[RID(r)])
    }
    bb := b.Bytes()
    if len(bb) > 1 {
        bb[len(bb)-2] = '}'
    }
    return string(bb)
}

type Bank struct {
    available  RMap
    max        map[PID]RMap
    allocation map[PID]RMap
    sync.Mutex
}

func (b *Bank) need(p PID, r RID) int {
    return b.max[p][r] - b.allocation[p][r]
}

func New(available RMap) (b *Bank, err error) {
    for r, a := range available {
        if a < 0 {
            return nil, fmt.Errorf("negative resource %s: %d", r, a)
        }
    }
    return &Bank{
        available:  available,
        max:        map[PID]RMap{},
        allocation: map[PID]RMap{},
    }, nil
}

func (b *Bank) NewProcess(p PID, max RMap) (err error) {
    b.Lock()
    defer b.Unlock()
    if _, ok := b.max[p]; ok {
        return fmt.Errorf("process %s already registered", p)
    }
    for r, m := range max {
        switch a, ok := b.available[r]; {
        case !ok:
            return fmt.Errorf("resource %s unknown", r)
        case m > a:
            return fmt.Errorf("resource %s: process %s max %d > available %d",
                r, p, m, a)
        }
    }
    b.max[p] = max
    b.allocation[p] = RMap{}
    return
}

func (b *Bank) Request(pid PID, change RMap) (err error) {
    b.Lock()
    defer b.Unlock()
    if _, ok := b.max[pid]; !ok {
        return fmt.Errorf("process %s unknown", pid)
    }
    for r, c := range change {
        if c < 0 {
            return errors.New("decrease not allowed")
        }
        if _, ok := b.available[r]; !ok {
            return fmt.Errorf("resource %s unknown", r)
        }
        if c > b.need(pid, r) {
            return errors.New("increase exceeds declared max")
        }
    }
    // allocation is non-exported data so we can change it in place
    // then change it back if the request cannot be granted.
    for r, c := range change {
        b.allocation[pid][r] += c // change in place
    }
    defer func() {
        if err != nil { // if request not granted,
            for r, c := range change {
                b.allocation[pid][r] -= c // change it back
            }
        }
    }()
    // Collect list of process IDs, also compute cash
    // First in the list is always the requesting PID.
    cash := RMap{}
    for r, a := range b.available {
        cash[r] = a
    }
    perm := make([]PID, len(b.allocation))
    i := 1
    for pr, a := range b.allocation {
        if pr == pid {
            perm[0] = pr
        } else {
            perm[i] = pr
            i++
        }
        for r, a := range a {
            cash[r] -= a
        }
    }
    ret := RMap{}  // sum of loans
    m := len(perm) // number of processes still candidates for termination
    for {
        // find a process h that can terminate
        h := 0
    h:
        for ; ; h++ {
            if h == m {
                // no process could terminate
                return errors.New("request would make deadlock possible")
            }
            for r := range b.available {
                if b.need(perm[h], r) > cash[r]+ret[r] {
                    // h cannot terminate if any resource need cannot be met.
                    continue h
                }
            }
            // log possible terimation, consistent with WP example program.
            log.Println(" ", perm[h], "could terminate")
            // all resource needs can be met.  h can terminate.
            break
        }
        if h == 0 { // Zwanenburg condition:
            // if requesting process can terminate, pattern is safe and
            // remaining terminations do not need to be demonstrated.
            return nil
        }
        for r, a := range b.allocation[perm[h]] {
            ret[r] += a
        }
        m--
        perm[h] = perm[m]
    }
}

package main

import (
    "fmt"
    "bank"
)

func main() {
    // Task example data:
    // create "bank" with available resources
    b, _ := bank.New(bank.RMap{"A": 6, "B": 5, "C": 7, "D": 6})

    // add processes with their maximum allocation limits
    b.NewProcess("P1", bank.RMap{"A": 3, "B": 3, "C": 2, "D": 2})
    b.NewProcess("P2", bank.RMap{"A": 1, "B": 2, "C": 3, "D": 4})
    b.NewProcess("P3", bank.RMap{"A": 1, "B": 3, "C": 5})

    // processes request resources.  Each request is checked for safety.
    // <nil> returned error value means request was safe and was granted.
    fmt.Println("P1 request:")
    fmt.Println(b.Request("P1", bank.RMap{"A": 1, "B": 2, "C": 2, "D": 1}))

    fmt.Println("\nP2 request:")
    fmt.Println(b.Request("P2", bank.RMap{"A": 1, "C": 3, "D": 3}))

    fmt.Println("\nP3 request:")
    fmt.Println(b.Request("P3", bank.RMap{"A": 1, "B": 2, "C": 1}))
}
Output:
P1 request:
2017/08/29 16:44:15   P1 could terminate
<nil>

P2 request:
2017/08/29 16:44:15   P2 could terminate
<nil>

P3 request:
2017/08/29 16:44:15   P1 could terminate
2017/08/29 16:44:15   P2 could terminate
2017/08/29 16:44:15   P3 could terminate
<nil>

J

The task description currently does not define the process being run. So we follow the example set by other implementations and have each process free all resources after successfully being run. Also, since this is a demo, we give a blow-by-blow description of what's happening as it runs. 

bankrun=:1 :0
  'MAX ALLOC TOTAL'=. y
   todo=.(#ALLOC)#1
   whilst. (+./todo)*-. prior-:todo do.
     prior=. todo
     for_p.I.todo do.
       avail=. TOTAL-+/ALLOC
       echo 'currently available: ',":avail
       pALLOC=. p{ALLOC
       pMAX=. p{MAX
       request=. pMAX-pALLOC
       if.(0>request)+.&(+./)request>avail do.
         echo 'unsafe request ',(":request),', skipping ',":p
         continue.
       else.
         echo 'running process ',(":p),', allocating ',":request
       end.
       free=.request u pALLOC
       echo 'process ',(":p),' freeing ',":free
       assert (0<:free) *&(*/) free <: pMAX
       ALLOC=. (pALLOC-free) p} ALLOC
       todo=. 0 p} todo
    end.
  end.
  if.+./todo do.
    echo 'deadlocked processes: ',":I.todo
  end.
  echo 'DONE'
)

Definitions for task example: 

max=: 3 3 2 2,1 2 3 4,:1 3 5 0
alloc=: 1 2 2 1,1 0 3 3,:1 2 1 0
total=:6 5 7 6

NB. simulate running process
NB. left arg: newly available resources, right: previously available
NB. result: resources freed
run=: +

Example run: 

   run bankrun max;alloc;total
currently available: 3 1 1 2
running process 0, allocating 2 1 0 1
process 0 freeing 3 3 2 2
currently available: 6 4 3 4
running process 1, allocating 0 2 0 1
process 1 freeing 1 2 3 4
currently available: 7 6 6 8
running process 2, allocating 0 1 4 0
process 2 freeing 1 3 5 0
DONE

Julia

Translation of: Kotlin
function queryprompt(query, typ)
    print(query, ": ")
    entry = uppercase(strip(readline(stdin)))
    return (typ <: Integer) ? parse(Int, entry) :
        (typ <: Vector) ? map(x -> parse(Int, x), split(entry, r"\s+")) :
        entry
end
 
function testbankers()
    r = queryprompt("Enter the number of resources", Int)
    p = queryprompt("\nEnter the number of processes", Int)
    maxres = queryprompt("\nEnter Claim Vector", Vector{Int})
    curr, maxclaim = zeros(Int, p, r), zeros(Int, p, r)
    
    for i in 1:p
        curr[i, :] .= queryprompt("\nEnter Allocated Resource Table, Row $i", Vector{Int})
    end
     for i in 1:p
        maxclaim[i, :] .= queryprompt("\nEnter Maximum Claim Table, Row $i", Vector{Int})
    end
 
    alloc = [sum(curr[:, j]) for j in 1:r]
    println("\nAllocated Resources: $alloc")
 
    avl = map(i -> maxres[i] - alloc[i], 1:r)
    println("\nAvailable Resources: $avl")
 
    running = trues(p)
    count = p
    while count != 0
        safe = false
        for i in 1:p
            if running[i]
                exec = true
                for j in 1:r
                    if maxclaim[i, j] - curr[i, j] > avl[j]
                        exec = false
                        break
                    end
                end
 
                if exec
                    println("\nProcess $i is executing.")
                    running[i] = false
                    count -= 1
                    safe = true
                    for j in 1:r
                        avl[j] += curr[i, j]
                    end
                    break
                end
            end
        end
 
        if !safe
            println("The processes are in an unsafe state.")
            break
        end
 
        println("\nThe process is in a safe state.")
        println("\nAvailable Vector: $avl")
    end
end

testbankers()
Output:
Enter the number of resources: 4

Enter the number of processes: 5

Enter Claim Vector: 8 5 9 7

Enter Allocated Resource Table, Row 1: 2 0 1 1

Enter Allocated Resource Table, Row 2: 0 1 2 1

Enter Allocated Resource Table, Row 3: 4 0 0 3

Enter Allocated Resource Table, Row 4: 0 2 1 0

Enter Allocated Resource Table, Row 5: 1 0 3 0


Enter Maximum Claim Table, Row 1: 3 2 1 4

Enter Maximum Claim Table, Row 2: 0 2 5 2

Enter Maximum Claim Table, Row 3: 5 1 0 5

Enter Maximum Claim Table, Row 4: 1 5 3 0

Enter Maximum Claim Table, Row 5: 3 0 3 3

Allocated Resources: [7, 3, 7, 5]

Available Resources: [1, 2, 2, 2]

Process 3 is executing.

The process is in a safe state.

Available Vector: [5, 2, 2, 5]

Process 1 is executing.

The process is in a safe state.

Available Vector: [7, 2, 3, 6]

Process 2 is executing.

The process is in a safe state.

Available Vector: [7, 3, 5, 7]

Process 4 is executing.

The process is in a safe state.

Available Vector: [7, 5, 6, 7]

Process 5 is executing.

The process is in a safe state.

Available Vector: [8, 5, 9, 7]

Kotlin

Translation of: C

For simplicity, input checking is ignored: 

// version 1.1.4-3

fun main(args: Array<String>) {
    print("Enter the number of resources: ")
    val r = readLine()!!.toInt()

    print("\nEnter the number of processes: ")
    val p = readLine()!!.toInt()

    print("\nEnter Claim Vector: ")
    val maxRes = readLine()!!.split(' ').map { it.toInt() } .toIntArray()

    println("\nEnter Allocated Resource Table:")
    val curr = Array(p) { IntArray(r) }
    for (i in 0 until p) {
        print("Row ${i + 1}:  ")
        curr[i] = readLine()!!.split(' ').map { it.toInt() }.toIntArray()
    }

    println("\nEnter Maximum Claim Table: ")
    val maxClaim = Array(p) { IntArray(r) }
    for (i in 0 until p) {
        print("Row ${i + 1}:  ")
        maxClaim[i] = readLine()!!.split(' ').map { it.toInt() }.toIntArray()
    }

    val alloc = IntArray(r)
    for (i in 0 until p) {
        for (j in 0 until r) alloc[j] += curr[i][j]
    }
    println("\nAllocated Resources: ${alloc.joinToString(" ")}")

    val avl = IntArray(r) { maxRes[it] - alloc[it] }
    println("\nAvailable Resources: ${avl.joinToString(" ")}")

    val running = BooleanArray(p) { true }
    var count = p
    while (count != 0) {
        var safe = false
        for (i in 0 until p) {
            if (running[i]) {
                var exec = true
                for (j in 0 until r) {
                    if (maxClaim[i][j] - curr[i][j] > avl[j]) {
                        exec = false
                        break
                    }
                }

                if (exec) {
                    print("\nProcess ${i + 1} is executing.\n")
                    running[i] = false
                    count--
                    safe = true
                    for (j in 0 until r) avl[j] += curr[i][j]
                    break
                }
            }
        }

        if (!safe) {
            print("The processes are in an unsafe state.")
            break
        }

        print("\nThe process is in a safe state.")
        println("\nAvailable Vector: ${avl.joinToString(" ")}")
    }
}

Sample input/output: 

Enter the number of resources: 4

Enter the number of processes: 5

Enter Claim Vector: 8 5 9 7

Enter Allocated Resource Table:
Row 1:  2 0 1 1
Row 2:  0 1 2 1
Row 3:  4 0 0 3
Row 4:  0 2 1 0
Row 5:  1 0 3 0

Enter Maximum Claim Table: 
Row 1:  3 2 1 4
Row 2:  0 2 5 2
Row 3:  5 1 0 5
Row 4:  1 5 3 0
Row 5:  3 0 3 3

Allocated Resources: 7 3 7 5

Available Resources: 1 2 2 2

Process 3 is executing.

The process is in a safe state.
Available Vector: 5 2 2 5

Process 1 is executing.

The process is in a safe state.
Available Vector: 7 2 3 6

Process 2 is executing.

The process is in a safe state.
Available Vector: 7 3 5 7

Process 4 is executing.

The process is in a safe state.
Available Vector: 7 5 6 7

Process 5 is executing.

The process is in a safe state.
Available Vector: 8 5 9 7

M2000 Interpreter 

Module BankerAlgo {
      Form 80, 44
      Cls 5
      Pen 14
      Function Request(FromWhere as Inventory, What$, Many as long)  {
            =FromWhere(What$)-FromWhere(What$+"_Request")-Many>=0
      }
      Function RequestPreset(FromWhere as Inventory, What$, Many as long)  {
            =FromWhere(What$+"_Request")-Many>=0
      }
      Function Need(FromWhere as Inventory, What$, Many) { 
            =FromWhere(What$ + "_max")-FromWhere(What$)-Many>=0
      }
      \\ code for sub can be found from parent module/function (here parent as in code, not as in call)
      Function NewProcess {
            Inventory Process
            ApplyResources(Process)   ' sub need more arguments and read from current stack
            =Process
      }
      Inventory System, Processes 
      \\ Recource, Max, Available
      ApplyResources(System, "A", 6, 3,"B", 5,1,"C", 7, 1, "D", 6, 2)
      \\ Recource, Max, Available
      Append Processes, "P1":=NewProcess("A", 3, 1, "B", 3, 2, "C", 2, 2, "D", 2,1)
      Append Processes, "P2":=NewProcess("A", 1, 1, "B", 2, 0, "C", 3, 3, "D", 4,3)
      Append Processes, "P3":=NewProcess("A", 1, 1, "B", 3, 2, "C", 5, 1, "D", 0,0)
      Status(True) ' show all process, available resource and max
      SafeState=True
      Print "Current Status"
      RequestResource() ' display Safe State
      RequestResource("P2", "D", 1) ' display Safe State
      RequestResource("P1", "A", 1, "D", 1) ' display Safe State
      RequestResource("P1", "C", 1, "D", 1) ' display Too many resources ...
      RequestResource("P2", "B", 1) ' display Unsafe State
      RequestResource("P3", "C", 1)  ' display Safe State
      Status()
      \\ Second Example
      Clear System, Processes
      ApplyResources(System, "A", 10, 3)
      Append Processes, "P1":=NewProcess("A", 9, 3)
      Append Processes, "P2":=NewProcess("A", 4, 2)
      Append Processes, "P3":=NewProcess("A", 7, 2)
      Status(True) ' show all process, available resource and max    
      Print "Current Status"
      RequestResource() ' display Safe State
      \ Third Example
      Clear System
      ApplyResources(System, "A", 10, 2)
      Return Processes, "P1":=NewProcess("A", 9,4)
      Status(True) ' show all process, available resource and max    
      Print "Current Status"
      RequestResource() ' display UnSafe State       
      Sub Respond()
            If SafeState Then {
                  Pen 15 {Print "Safe State"}
            } Else Pen 13 {Print "Unsafe State"}
      End Sub
      Sub WaitForKey()
            Pen 11 {Print "Press a key"}
            local a$=key$
      End Sub
      Sub RequestResource(ProcessName$="" )
            SafeState=True
            If ProcessName$="" Then CheckNewState(&SafeState) : Respond() : Print : WaitForKey():Exit Sub
            Local pro=Processes(ProcessName$), ResourceName$, many as long
            ClearAllRequest(pro)
            Local skip=False
            While Match("SN") {
                  Read ResourceName$, many
                  Print  Format$("Claim {1} for type {0} resource ",ResourceName$, many)
                  If skip Then Continue
                  If Request(System, ResourceName$, many) Then {
                        If Need(pro, ResourceName$, many) Then { 
                              Return pro, ResourceName$+"_Request":=many
                              Return System, ResourceName$+"_Request":=-many
                        } Else {
                              Print "Too many Recources "+ResourceName$+" for Process "+ProcessName$  : Skip=True
                        }
                  } Else Print "Too many Recources for System" : Skip=True
                  If Skip Then exit
            } 
            If skip Else  CheckNewState(&SafeState) : Respond()
            Print  ' just a new line
            WaitForKey()
      End Sub
      Sub ApplyResources(Where as Inventory, What$, MaxValue, InitialValue)
            Repeat {
                  If Not Exist(Where, What$) Then {
                        Append Where, What$:=InitialValue, What$+"_max":=MaxValue, What$+"_Request":=0
                  }
                  If not Match("SNN") Then Exit
                  Read What$, MaxValue, InitialValue
            }  Always
      End Sub
      Sub ClearAllRequest(Where  as Inventory)
            Local M=Each(Where)
            While M {
                  If Instr(Eval$(M, M^),"_")=0 Then {
                        Return Where, Eval$(M,M^)+"_Request":=0
                  }
            }
      End Sub
      Sub PrintResources(Where  as Inventory)
            Local M=Each(Where)
            While M {
                  If Instr(Eval$(M, M^),"_")=0 Then Print Eval$(M, M^)+"="+Eval$(M),
            }
            Print
      Exit Sub
      Sub PrintMax(Where  as Inventory)
            Local M=Each(Where)
            While M {
                  If Instr(Eval$(M, M^),"_max")>0 Then Print LeftPart$(Eval$(M, M^), "_")+"="+Eval$(M),
            }
            Print
      Exit Sub
      Sub Status(Ok as boolean=False)
            Print "Total System Resources"
            PrintMax(System)
            Print "Available Resources in System"
            PrintResources(System)
            If Not Ok Then WaitForKey(): Exit Sub
            Local  M=Each(Processes)
            While M {
                  Print "Process "+Eval$(M, M^)
                  PrintResources(Processes(M^!))  ' give index M^ as Key index number (using !)
                  Print "Maximum Resources for "+Eval$(M, M^)
                  PrintMax(Processes(M^!))
            }
      End Sub
      Sub CheckNewState(&Ok)
            local M=Each(Processes), M1, count=len(Processes), alive(0 to count-1)=1
            Local Z, Recource$, safe as boolean=false
            While count {
                  safe=false
                  While M {
                        If alive(M^) Then {
                              Z=Processes(M^!)
                              M1=Each(Z) 
                              safe=True 
                              While M1 {
                                    Recource$=Eval$(M1, M1^)
                                    If Instr(Recource$,"_")=0 Then {
                                         safe=System(Recource$)+System(Recource$+"_Request") >= Z(Recource$ + "_max") - Z(Recource$)-Z(Recource$ + "_Request")
		               }
                                    If not safe Then exit
                              }
                              If safe Then {
                                    print format$("Process {0} is executing", M^+1)
                                    alive(M^)=0
                                    count--
                                    M1=Each(Z) 
                                    While M1 {
                                          Recource$=Eval$(M1, M1^)
                                          If Instr(Recource$,"_")=0 Then {
                                                Return System, Recource$+"_Request":= System(Recource$+"_Request") + Z(Recource$) + Z(Recource$+"_Request")
                                                Return Z, Recource$+"_Request":=0
                                          }
                                    }
                              }
                        }
                  }
                  If safe Else exit
            }
            Ok=safe
            ClearAllRequest(System)
      End Sub
}
BankerAlgo

Nim

Translation of: Kotlin
import sequtils, strformat, strutils, sugar

stdout.write "Enter the number of resources: "
let r = stdin.readLine().parseInt()

stdout.write "Enter the number of processes: "
stdout.flushFile()
let p = stdin.readLine().parseInt()

stdout.write "Enter Claim Vector: "
let maxRes = stdin.readLine().splitWhitespace().map(parseInt)

echo "Enter Allocated Resource Table:"
var curr = newSeqWith(p, newSeq[int](r))
for i in 0..<p:
  stdout.write &"Row {i + 1}: "
  curr[i] = stdin.readLine().splitWhitespace().map(parseInt)

echo "Enter Maximum Claim Table:"
var maxClaim = newSeqWith(p, newSeq[int](r))
for i in 0..<p:
  stdout.write &"Row {i + 1}:  "
  maxClaim[i] = stdin.readLine().splitWhitespace().map(parseInt)

var alloc = newSeq[int](r)
for i in 0..<p:
  for j in 0..<r:
    alloc[j] += curr[i][j]
echo &"\nAllocated Resources: {alloc.join(\" \")}"

var avl = collect(newSeq, for i in 0..<r: maxRes[i] - alloc[i])
echo &"Available Resources: {avl.join(\" \")}"

var running = repeat(true, p)
var count = p
while count > 0:
  var safe = false
  for i in 0..<p:
    if running[i]:
      var exec = true
      for j in 0..<r:
        if maxClaim[i][j] - curr[i][j] > avl[j]:
          exec = false
          break
      if exec:
        echo &"\nProcess {i + 1} is executing."
        running[i] = false
        dec count
        safe = true
        for j in 0..<r: avl[j] += curr[i][j]
        break

  if not safe:
    echo "The processes are in an unsafe state."
    break

  echo "\nThe process is in a safe state."
  echo &"Available Vector: {avl.join(\" \")}"
Output:
Enter the number of resources: 4
Enter the number of processes: 5
Enter Claim Vector: 8 5 9 7
Enter Allocated Resource Table:
Row 1: 2 0 1 1
Row 2: 0 1 2 1
Row 3: 4 0 0 3
Row 4: 0 2 1 0
Row 5: 1 0 3 0
Enter Maximum Claim Table:
Row 1:  3 2 1 4
Row 2:  0 2 5 2
Row 3:  5 1 0 5
Row 4:  1 5 3 0
Row 5:  3 0 3 3

Allocated Resources: 7 3 7 5
Available Resources: 1 2 2 2

Process 3 is executing.

The process is in a safe state.
Available Vector: 5 2 2 5

Process 1 is executing.

The process is in a safe state.
Available Vector: 7 2 3 6

Process 2 is executing.

The process is in a safe state.
Available Vector: 7 3 5 7

Process 4 is executing.

The process is in a safe state.
Available Vector: 7 5 6 7

Process 5 is executing.

The process is in a safe state.
Available Vector: 8 5 9 7

Perl

Translation of: Raku
use strict;
use warnings;
use feature 'say';

my @avail =  (3, 1, 1, 2);                              # Available instances of resource
my @maxm  = ([3, 3, 2, 2], [1, 2, 3, 4], [1, 3, 5, 0]); # Maximum R that can be allocated to processes
my @allot = ([1, 2, 2, 1], [1, 0, 3, 3], [1, 2, 1, 0]); # Resources allocated to processes

# Function to find the system is in safe state or not
sub isSafe {
    my($work, $maxm, $allot) = @_;
    my $P = @$allot;            # Number of processes
    my $R = @$work;             # Number of resources
    my @unfinished = (1) x $P;  # Mark all processes as unfinished
    my(@safeSeq,@need);
    for my $i (0..$P-1) {       # Calculating need of each process:
        for my $j (0..$R-1) {   #    maxm instance - allocated instance
           $need[$i][$j] = $$maxm[$i][$j]   - $$allot[$i][$j]
        }
    }

    # While all processes are not finished or system is not in safe state
    my $count = 0;
    while ($count < $P) {
        my $found = 0;
        for my $p (0..$P-1) {
            # While a process is not finished
            if ($unfinished[$p]) {
                # Check if for all resources of current P need is less than work
                my $satisfied;
                LOOP: for my $j (0..$R-1) {
                    $satisfied = $j;
                    last LOOP if $need[$p][$j] > $$work[$j]
                }
                # If all needs of p were satisfied
                if ($satisfied == $R-1) {
                    $$work[$_] += $$allot[$p][$_] for 0..$R-1; # free the resources
                    say 'available resources: ' . join ' ', @$work;
                    push @safeSeq, $p;                         # Add this process to safe sequence
                    $unfinished[$p]  = 1;                      # Mark this process as finished
                    $count += 1;
                    $found = 1
                }
            }
        }
        # If we could not find a next process in safe sequence.
        return 0, "System is not in safe state." unless $found;
    }
    # If system is in safe state then safe sequence will be as below
    return 1, "Safe sequence is: " . join ' ', @safeSeq
}

# Check system is in safe state or not
my($safe_state,$status_message) = isSafe(\@avail, \@maxm, \@allot);
say "Safe state? " . ($safe_state ? 'True' : 'False');
say "Message:    $status_message";
Output:
available resources: 4 3 3 3
available resources: 5 3 6 6
available resources: 6 5 7 6
Safe state? True
Message:    Safe sequence is: 0 1 2

Phix 

with javascript_semantics
sequence max_res = {6, 5, 7, 6},
         curr = {{1, 2, 2, 1},
                 {1, 0, 3, 3},
                 {1, 2, 1, 0}},
        running = repeat(true,length(curr)),
        max_claim = {{3, 3, 2, 2},
                     {1, 2, 3, 4},
                     {1, 3, 5, 0}},
        alloc = repeat(0,length(max_res))
 
integer count = length(curr)
for i=1 to count do
    alloc = sq_add(alloc,curr[i])
end for
sequence avl = sq_sub(max_res,alloc) 

printf(1,"Available system resources: %V\n",{max_res})
printf(1,"Process allocated: %V\n",{curr})
printf(1,"Maximum resources: %V\n",{max_claim})
printf(1,"Allocated resources: %V\n",{alloc})
printf(1,"Available resources: %V\n",{avl})

while count!=0 do
    bool safe = false
    for i=1 to length(curr) do
        if running[i] then
            bool execute = true
            for j=1 to length(max_res) do
                if max_claim[i][j]-curr[i][j] > avl[j] then
                    execute = false
                    exit
                end if
            end for

            if execute then
                printf(1,"Process%d is executing. ", i)
                running[i] = false
                count -= 1
                safe = true
                for j=1 to length(max_res) do
                    avl[j] += curr[i][j]
                end for
                exit
            end if
        end if
    end for

    if not safe then
        printf(1,"The processes are in an unsafe state.\n")
        exit
    end if
    printf(1, "Safe state. Available resources: %V\n",{avl})
end while
Output:
Available system resources: {6,5,7,6}
Process allocated: {{1,2,2,1},{1,0,3,3},{1,2,1,0}}
Maximum resources: {{3,3,2,2},{1,2,3,4},{1,3,5,0}}
Allocated resources: {3,4,6,4}
Available resources: {3,1,1,2}
Process1 is executing. Safe state. Available resources: {4,3,3,3}
Process2 is executing. Safe state. Available resources: {5,3,6,6}
Process3 is executing. Safe state. Available resources: {6,5,7,6}

Changing the initial curr[2] to {1, 1, 3, 3}: 

Available system resources: {6,5,7,6}
Process allocated: {{1,2,2,1},{1,1,3,3},{1,2,1,0}}
Maximum resources: {{3,3,2,2},{1,2,3,4},{1,3,5,0}}
Allocated resources: {3,5,6,4}
Available resources: {3,0,1,2}
The processes are in an unsafe state.

Python 

def main():
    resources = int(input("Number of resources: "))
    processes = int(input("Number of processes: "))
    max_resources = [int(i) for i in input("Maximum resources: ").split()]

    print("\n-- resources allocated for each process --")
    currently_allocated = [[int(i) for i in input(f"process {j + 1}: ").split()] for j in range(processes)]

    print("\n--- maximum resources for each process ---")
    max_need = [[int(i) for i in input(f"process {j + 1}: ").split()] for j in range(processes)]

    allocated = [0] * resources
    for i in range(processes):
        for j in range(resources):
            allocated[j] += currently_allocated[i][j]
    print(f"\nTotal resources allocated: {allocated}")

    available = [max_resources[i] - allocated[i] for i in range(resources)]
    print(f"Total resources available: {available}\n")

    running = [True] * processes
    count = processes
    while count != 0:
        safe = False
        for i in range(processes):
            if running[i]:
                executing = True
                for j in range(resources):
                    if max_need[i][j] - currently_allocated[i][j] > available[j]:
                        executing = False
                        break
                if executing:
                    print(f"process {i + 1} running")
                    running[i] = False
                    count -= 1
                    safe = True
                    for j in range(resources):
                        available[j] += currently_allocated[i][j]
                    break
        if not safe:
            print("The process is in an unsafe state.")
            break

        print(f"The process is in a safe state.\nAvailable resources: {available}\n\n")


if __name__ == '__main__':
    main()
Output:
Number of resources: 4
Number of processes: 3
Maximum resources: 6 5 7 6

-- resources allocated for each process  --
process 1: 1 2 2 1
process 2: 1 0 3 3
process 3: 1 2 1 0

--- maximum resources for each process ---
process 1: 3 3 2 2
process 2: 1 2 3 4
process 3: 1 3 5 0

Total resources allocated: [3, 4, 6, 4]
Total resources available: [3, 1, 1, 2]

process 1 running
The process is in a safe state.
Available resources: [4, 3, 3, 3]

process 2 running
The process is in a safe state.
Available resources: [5, 3, 6, 6]

process 3 running
The process is in a safe state.
Available resources: [6, 5, 7, 6]

Racket 

#lang racket/base
(require racket/block racket/pretty racket/port racket/vector)

(pretty-print-columns 20) ; make the matrices look a bit more matrixey

(define (bankers-algorithm p r maxres curr maxclaim)
  (define running? (make-vector p #t))
  (define alloc (for/vector #:length r ((j (in-range r)))
                  (for/sum ((cu_i (in-vector curr))) (vector-ref cu_i j))))
  (printf "Allocated resources:~%~a~%" (pretty-format alloc))
  (define avl (for/vector #:length r ((m (in-vector maxres)) (a (in-vector alloc))) (- m a)))
  (printf "Available resources:~%~a~%~%" (pretty-format avl))
  
  (define (safe-exec i mc_i cu_i)
    (define exec? (for/and ((a (in-vector avl)) (m (in-vector mc_i)) (c (in-vector cu_i)))
                    (<= (- m c) a)))
    (cond
      [exec?
       (printf "Process ~a is executing~%" (add1 i))
       (vector-set! running? i #f)
       (for ((j (in-range r)) (a (in-vector avl)) (c (in-vector cu_i))) (vector-set! avl j (+ a c)))
       #t]
      [else #f]))
  
  (let loop ()
    (unless (zero? (vector-count values running?))
      (define safe?
        (for/first ((i (in-range p))
                    (r? (in-vector running?))
                    (mc_i (in-vector maxclaim))
                    (cu_i (in-vector curr))
                    ;; the break condition for this is identical to safe?, so we have no
                    ;; separate break? flag
                    #:when r?
                    #:when (safe-exec i mc_i cu_i))
          #t))
      (cond [safe?
             (printf "The process is in a safe state~%~%Available vector: ~a~%" (pretty-format avl))
             (loop)]
            [else (displayln "The processes are in an unsafe state")]))))


(define (bankers-input)  
  (define ((n-vector? type? dims) x) ;; not the world's most efficient implementation!
    (cond [(null? dims) (type? x)]
          [(not (vector? x)) #f]
          [(not (= (car dims) (vector-length x))) #f]
          [else (for/and ((e (in-vector x))) (n-vector? type? (cdr dims)) e)]))
  
  (define-syntax-rule (prompted-input prompt valid?)
    (block
     (printf "Enter ~a:~%" prompt)
     (define rv (read))
     (pretty-print rv)
     (unless (valid? rv) (raise-argument-error 'prompted-input (format "~a" 'valid?) rv))
     rv))
  
  (define p (prompted-input "the number of processes" exact-positive-integer?))
  (define r (prompted-input "the number of resources" exact-positive-integer?))
  (define maxres (prompted-input "Claim Vector" (n-vector? exact-positive-integer? (list r))))
  (define curr (prompted-input "Allocated Resource Table"
                               (n-vector? exact-positive-integer? (list p r))))
  (define maxclaim (prompted-input "Maximum Claim Table"
                                   (n-vector? exact-positive-integer? (list p r))))
  (values p r maxres curr maxclaim))

(module+ main
  (with-input-from-string
   #<<EOS
5
4
#(8 5 9 7)
#(#(2 0 1 1)
  #(0 1 2 1)
  #(4 0 0 3)
  #(0 2 1 0)
  #(1 0 3 0))
#(#(3 2 1 4)
  #(0 2 5 2)
  #(5 1 0 5)
  #(1 5 3 0)
  #(3 0 3 3))

EOS
   (λ () (call-with-values bankers-input bankers-algorithm))))
Output:
Enter the number of processes:
5
Enter the number of resources:
4
Enter Claim Vector:
'#(8 5 9 7)
Enter Allocated Resource Table:
'#(#(2 0 1 1)
   #(0 1 2 1)
   #(4 0 0 3)
   #(0 2 1 0)
   #(1 0 3 0))
Enter Maximum Claim Table:
'#(#(3 2 1 4)
   #(0 2 5 2)
   #(5 1 0 5)
   #(1 5 3 0)
   #(3 0 3 3))
Allocated resources:
'#(7 3 7 5)
Available resources:
'#(1 2 2 2)

Process 3 is executing
The process is in a safe state

Available vector: '#(5 2 2 5)
Process 1 is executing
The process is in a safe state

Available vector: '#(7 2 3 6)
Process 2 is executing
The process is in a safe state

Available vector: '#(7 3 5 7)
Process 4 is executing
The process is in a safe state

Available vector: '#(7 5 6 7)
Process 5 is executing
The process is in a safe state

Available vector: '#(8 5 9 7)

Raku

(formerly Perl 6) Based on the Python3 solution by Shubham Singh found here 

my @avail = <3 1 1 2>;                        # Available instances of resource
my @maxm  = <3 3 2 2>, <1 2 3 4>, <1 3 5 0>;  # Maximum resources that can be allocated to processes
my @allot = <1 2 2 1>, <1 0 3 3>, <1 2 1 0>;  # Resources allocated to processes

# Function to find the system is in safe state or not
sub isSafe(\work is copy, \maxm, \allot) {
    my \P          = allot.elems;     # Number of processes
    my \Pool       = (^P).SetHash;    # Process pool
    my \R          = work.elems;      # Number of resources 
    my \need       = maxm »-« allot;  # the need matrix
    my @safe-sequence;

    # While all processes are not finished or system is not in safe state
    my $count = 0;
    while $count < P {
        my $found = False;
        for Pool.keys -> \p {           
            if all need[p] »≤« work {    # now process can be finished
                work »+=« allot[p;^R];   # Free the resources
                say 'available resources: ' ~ work;
                @safe-sequence.push: p;  # Add this process to safe sequence
                Pool{p}--;               # Remove this process from Pool
                $count += 1;
                $found = True
            }
        }
        # If we could not find a next process in safe sequence
        return False, "System is not in safe state." unless $found;
    }
    # If system is in safe state then safe sequence will be as below
    return True, "Safe sequence is: " ~ @safe-sequence
}

# Check if system is in a safe state
my ($safe-state,$status-message) = isSafe @avail, @maxm, @allot;
say "Safe state? $safe-state";
say "Message:    $status-message";
Output:
available resources: 4 3 3 3
available resources: 5 3 6 6
available resources: 6 5 7 6
Safe state? True
Message:    Safe sequence is: 0 1 2

Rust

Adapted from the C language version. It crashes for invalid input. 

fn read_numbers<T>() -> Vec<T>
where T: std::str::FromStr {
    use std::io::Write;
    std::io::stdout().flush().unwrap();

    let mut line = String::new();
    std::io::stdin().read_line(&mut line).unwrap();
    line.split(" ").map(|word| word.trim().parse::<T>().ok().unwrap()).collect()
}

fn main() {
    print!("Enter the number of resources: ");
    let r = read_numbers()[0];
    
    print!("Enter the number of processes: ");
    let p = read_numbers()[0];
    let mut running = vec![true; p];
    let mut count = p;
    
    print!("Enter the {}-item claim vector: ", r);
    let max_res = read_numbers::<u32>();

    println!("Enter the {}-line {}-column allocated-resource table:", p, r);
    let mut curr = vec![vec![0; 0]; p];
    for i in 0..p {
        curr[i] = read_numbers::<u32>();
    }
    
    println!("Enter the {}-line {}-column maximum-claim table:", p, r);
    let mut max_claim = vec![vec![0; 0]; p];
    for i in 0..p {
        max_claim[i] = read_numbers::<u32>();
    }
    
    print!("The claim vector is: ");
    for i in 0..r {
        print!("{} ", max_res[i]);
    }
    println!();

    println!("The allocated resources table is:");
    for i in 0..p {
        for j in 0..r {
            print!("\t{}", curr[i][j]);
        }
        println!();
    }

    println!("The maximum claims table is:");
    for i in 0..p {
        for j in 0..r {
            print!("\t{}", max_claim[i][j]);
        }
        println!();
    }
    
    let mut alloc = vec![0; r];
    for i in 0..p {
        for j in 0..r {
            alloc[j] += curr[i][j];
        }
    }
    
    print!("The allocated resources are: ");
    for i in 0..r {
        print!("{} ", alloc[i]);
    }
    println!();
    let mut avl = vec![0; r];
    for i in 0..r {
        avl[i] = max_res[i] - alloc[i];
    }

    print!("The available resources are: ");
    for i in 0..r {
        print!("{} ", avl[i]);
    }
    println!();

    while count != 0 {
        let mut safe = false;
        for i in 0..p {
            if running[i] {
                let mut exec = true;
                for j in 0..r {
                    if max_claim[i][j] - curr[i][j] > avl[j] {
                        exec = false;
                        break;
                    }
                }

                if exec {
                    println!("Process {} is executing.", i + 1);
                    running[i] = false;
                    count -= 1;
                    safe = true;
                    for j in 0..r {
                        avl[j] += curr[i][j];
                    }
                    break;
                }
            }
        }

        if safe {
            println!("The process is in safe state.");
        }
        else {
            println!("The processes are in unsafe state.");
            break;
        }

        print!("The available vector is: ");
        for i in 0..r {
            print!("{} ", avl[i]);
        }
        println!();
    }
}
Input and Output:
Enter the number of resources: 4
Enter the number of processes: 5
Enter the 4-item claim vector: 8 5 9 7
Enter the 5-line 4-column allocated-resource table:
2 0 1 1
0 1 2 1
4 0 0 3
0 2 1 0
1 0 3 0
Enter the 5-line 4-column maximum-claim table:
3 2 1 4
0 2 5 2
5 1 0 5
1 5 3 0
3 0 3 3
The claim vector is: 8 5 9 7 
The allocated resources table is:
	2	0	1	1
	0	1	2	1
	4	0	0	3
	0	2	1	0
	1	0	3	0
The maximum claims table is:
	3	2	1	4
	0	2	5	2
	5	1	0	5
	1	5	3	0
	3	0	3	3
The allocated resources are: 7 3 7 5 
The available resources are: 1 2 2 2 
Process 3 is executing.
The process is in safe state.
The available vector is: 5 2 2 5 
Process 1 is executing.
The process is in safe state.
The available vector is: 7 2 3 6 
Process 2 is executing.
The process is in safe state.
The available vector is: 7 3 5 7 
Process 4 is executing.
The process is in safe state.
The available vector is: 7 5 6 7 
Process 5 is executing.
The process is in safe state.
The available vector is: 8 5 9 7

Scala

Translation of: Python
import scala.io.StdIn.readLine

object BankersAlgorithm {
  def main(args: Array[String]): Unit = {
    println("Number of resources: ")
    val resources = readLine().toInt

    println("Number of processes: ")
    val processes = readLine().toInt

    println("Maximum resources: ")
    val maxResources = readLine().split(" ").map(_.toInt)

    println("\n-- resources allocated for each process --")
    val currentlyAllocated = Array.ofDim[Int](processes, resources)
    for (i <- 0 until processes) {
      println(s"process ${i + 1}: ")
      currentlyAllocated(i) = readLine().split(" ").map(_.toInt)
    }

    println("\n--- maximum resources for each process ---")
    val maxNeed = Array.ofDim[Int](processes, resources)
    for (i <- 0 until processes) {
      println(s"process ${i + 1}: ")
      maxNeed(i) = readLine().split(" ").map(_.toInt)
    }

    val allocated = Array.fill(resources)(0)
    for (i <- 0 until processes) {
      for (j <- 0 until resources) {
        allocated(j) += currentlyAllocated(i)(j)
      }
    }
    println(s"\nTotal resources allocated: ${allocated.mkString(", ")}")

    val available = maxResources.zip(allocated).map { case (max, alloc) => max - alloc }
    println(s"Total resources available: ${available.mkString(", ")}\n")

    var running = Array.fill(processes)(true)
    var count = processes

    while (count != 0) {
      var safe = false
      for (i <- 0 until processes if running(i)) {
        var executing = true
        for (j <- 0 until resources) {
          if (maxNeed(i)(j) - currentlyAllocated(i)(j) > available(j)) {
            executing = false
          }
        }
        if (executing) {
          println(s"process ${i + 1} is running")
          running(i) = false
          count -= 1
          safe = true
          for (j <- 0 until resources) {
            available(j) += currentlyAllocated(i)(j)
          }
        }
      }

      if (!safe) {
        println("The processes are in an unsafe state.")
        return
      }

      println(s"The processes are in a safe state.\nAvailable resources: ${available.mkString(", ")}\n")
    }
  }
}

input 

4
3
6 5 7 6
1 2 2 1
1 0 3 3
1 2 1 0
3 3 2 2
1 2 3 4
1 3 5 0
Output:
Number of resources: 4
Number of processes: 3
Maximum resources: 6 5 7 6

-- resources allocated for each process --
process 1: 1 2 2 1
process 2: 1 0 3 3
process 3: 1 2 1 0

--- maximum resources for each process ---
process 1: 3 3 2 2
process 2: 1 2 3 4
process 3: 1 3 5 0

Total resources allocated: 3, 4, 6, 4
Total resources available: 3, 1, 1, 2

process 1 is running
process 2 is running
process 3 is running
The processes are in a safe state.
Available resources: 6, 5, 7, 6

Swift 

import Foundation

print("Enter the number of resources: ", terminator: "")

guard let resources = Int(readLine(strippingNewline: true)!) else {
  fatalError()
}

print("Enter the number of processes: ", terminator: "")

guard let processes = Int(readLine(strippingNewline: true)!) else {
  fatalError()
}

var running = Array(repeating: true, count: processes)
var curr = Array(repeating: [Int](), count: processes)
var alloc = Array(repeating: 0, count: resources)
var available = Array(repeating: 0, count: resources)
var maxClaims = Array(repeating: [Int](), count: processes)
var count = processes

print("Enter the \(resources)-item claim vector: ", terminator: "")

guard let maxRes = readLine(strippingNewline: true)?.components(separatedBy: " ").compactMap(Int.init),
      maxRes.count == resources else {
  fatalError()
}

print("Enter the \(processes)-line \(resources)-column allocated-resource table:")

for i in 0..<processes {
  print("Row \(i + 1): ", terminator: "")

  guard let allc = readLine(strippingNewline: true)?.components(separatedBy: " ").compactMap(Int.init),
        maxRes.count == resources else {
    fatalError()
  }

  curr[i] = allc
}

print("Enter the \(processes)-line \(resources)-column maximum-claim table:")

for i in 0..<processes {
  print("Row \(i + 1): ", terminator: "")

  guard let clms = readLine(strippingNewline: true)?.components(separatedBy: " ").compactMap(Int.init),
        maxRes.count == resources else {
    fatalError()
  }

  maxClaims[i] = clms
}

for i in 0..<processes {
  for j in 0..<resources {
    alloc[j] += curr[i][j]
  }
}

for i in 0..<resources {
  available[i] = maxRes[i] - alloc[i]
}

print("The claim vector is: \(maxRes)")
print("The allocated resources table is: \(curr)")
print("The maximum claims table is: \(maxClaims)")
print("The allocated resources are: \(alloc)")
print("The available resources are: \(available)")

while count != 0 {
  var safe = false

  for i in 0..<processes where running[i] {
    var exec = true

    for j in 0..<resources where maxClaims[i][j] - curr[i][j] > available[j] {
      exec = false
      break
    }

    if exec {
      print("Process \(i + 1) is executing.")
      running[i] = false
      count -= 1
      safe = true

      for j in 0..<resources {
        available[j] += curr[i][j]
      }

      break
    }
  }

  if safe {
    print("The process is in safe state.")
  } else {
    print("The processes are in unsafe state.")
    break
  }

  print("The available vector is: \(available)")
}
Input and Output:
Enter the number of resources: 4
Enter the number of processes: 5
Enter the 4-item claim vector: 8 5 9 7
Enter the 5-line 4-column allocated-resource table:
Row 1: 2 0 1 1
Row 2: 0 1 2 1
Row 3: 4 0 0 3
Row 4: 0 2 1 0
Row 5: 1 0 3 0
Enter the 5-line 4-column maximum-claim table:
Row 1: 3 2 1 4
Row 2: 0 2 5 2
Row 3: 5 1 0 5
Row 4: 1 5 3 0
Row 5: 3 0 3 3
The claim vector is: [8, 5, 9, 7]
The allocated resources table is: [[2, 0, 1, 1], [0, 1, 2, 1], [4, 0, 0, 3], [0, 2, 1, 0], [1, 0, 3, 0]]
The maximum claims table is: [[3, 2, 1, 4], [0, 2, 5, 2], [5, 1, 0, 5], [1, 5, 3, 0], [3, 0, 3, 3]]
The allocated resources are: [7, 3, 7, 5]
The available resources are: [1, 2, 2, 2]
Process 3 is executing.
The process is in safe state.
The available vector is: [5, 2, 2, 5]
Process 1 is executing.
The process is in safe state.
The available vector is: [7, 2, 3, 6]
Process 2 is executing.
The process is in safe state.
The available vector is: [7, 3, 5, 7]
Process 4 is executing.
The process is in safe state.
The available vector is: [7, 5, 6, 7]
Process 5 is executing.
The process is in safe state.
The available vector is: [8, 5, 9, 7]

Wren

Translation of: Kotlin
import "io" for Stdin, Stdout

System.write("Enter the number of resources: ")
Stdout.flush()
var r = Num.fromString(Stdin.readLine())

System.write("\nEnter the number of processes: ")
Stdout.flush()
var p = Num.fromString(Stdin.readLine())

System.write("\nEnter Claim Vector: ")
Stdout.flush()
var maxRes = Stdin.readLine().split(" ").map { |s| Num.fromString(s) }.toList

System.print("\nEnter Allocated Resource Table:")
var curr = List.filled(p, null)
for (i in 0...p) {
    System.write("Row %(i + 1):  ")
    Stdout.flush()
    curr[i] = Stdin.readLine().split(" ").map { |s| Num.fromString(s) }.toList
}

System.print("\nEnter Maximum Claim Table: ")
var maxClaim = List.filled(p, null)
for (i in 0...p) {
    System.write("Row %(i + 1):  ")
    Stdout.flush()
    maxClaim[i] = Stdin.readLine().split(" ").map { |s| Num.fromString(s) }.toList
}

var alloc = List.filled(r, 0)
for (i in 0...p) {
    for (j in 0...r) alloc[j] = alloc[j] + curr[i][j]
}
System.print("\nAllocated Resources: %(alloc.join(" "))")

var avl = List.filled(r, 0)
for (i in 0...r) avl[i] = maxRes[i] - alloc[i]
System.print("\nAvailable Resources: %(avl.join(" "))")

var running = List.filled(p, true)
var count = p
while (count != 0) {
    var safe = false
    for (i in 0...p) {
        if (running[i]) {
            var exec = true
            for (j in 0...r) {
                if (maxClaim[i][j] - curr[i][j] > avl[j]) {
                    exec = false
                    break
                }
            }

            if (exec) {
                System.print("\nProcess %(i + 1) is executing.")
                running[i] = false
                count = count - 1
                safe = true
                for (j in 0...r) avl[j] = avl[j] + curr[i][j]
                break
            }
        }
    }

    if (!safe) {
        System.print("\nThe processes are in an unsafe state.")
        break
    }

    System.write("\nThe process is in a safe state.")
    System.print("\nAvailable Vector: %(avl.join(" "))")
}
Output:

Sample input/output: 

Enter the number of resources: 4

Enter the number of processes: 5

Enter Claim Vector: 8 5 9 7

Enter Allocated Resource Table:
Row 1:  2 0 1 1
Row 2:  0 1 2 1
Row 3:  4 0 0 3
Row 4:  0 2 1 0
Row 5:  1 0 3 0

Enter Maximum Claim Table: 
Row 1:  3 2 1 4
Row 2:  0 2 5 2
Row 3:  5 1 0 5
Row 4:  1 5 3 0
Row 5:  3 0 3 3

Allocated Resources: 7 3 7 5

Available Resources: 1 2 2 2

Process 3 is executing.

The process is in a safe state.
Available Vector: 5 2 2 5

Process 1 is executing.

The process is in a safe state.
Available Vector: 7 2 3 6

Process 2 is executing.

The process is in a safe state.
Available Vector: 7 3 5 7

Process 4 is executing.

The process is in a safe state.
Available Vector: 7 5 6 7

Process 5 is executing.

The process is in a safe state.
Available Vector: 8 5 9 7

Yabasic

Translation of: FreeBASIC
TODO:

Translate all Spanish texts to English

clear screen
input "Ingrese la cantidad de recursos: " r
input "Ingrese la cantidad de procesos: " p

print "\nIngrese los recursos m ximos: "
dim maxRes(r)
for i = 1 to r
    input "  " maxRes(i)
next i

print "\n-- recursos asignados para cada proceso  --"
dim curr(p, r)
for i = 1 to p
    print "proceso ", i, ":"
    for j = 1 to r
        input "  " curr(i, j)
    next j
    print
next i

print "\n--- recursos m ximos para cada proceso  ---"
dim maxReclam(p, r)
for i = 1 to p
    print "proceso ", i, ":"
    for j = 1 to r
        input "  " maxReclam(i, j)
    next j
    print
next i

print "\nRecursos totales asignados  : ";
dim recAsigad(r)
for i = 1 to p
    for j = 1 to r
        recAsigad(j) = recAsigad(j) + curr(i, j)
    next j
next i
for i = 1 to r
    print recAsigad(i), " ";
next i

dim recDispon(r)
print "\nRecursos totales disponibles: ";
for i = 1 to r
    recDispon(i) = maxRes(i) - recAsigad(i)
    print recDispon(i), " ";
next i

dim ejecutando(p)
for i = 1 to p
    ejecutando(i) = True
next i

contar = p
while contar <> 0
    seguro = False
    for i = 1 to p 
        if ejecutando(i) then
            ejecuta = True
            for j = 1 to r
                if (maxReclam(i,j) - curr(i,j) > recDispon(j)) then
                    ejecuta = False
                    break
                end if
            next j
            
            if ejecuta then
				print color("cya") "\n\nproceso ", i, " ejecut ndose."
                ejecutando(i) = False
                contar = contar - 1
                seguro = True
                for j = 0 to r
                    recDispon(j) = recDispon(j) + curr(i,j)
                next j
                break
            end if
        end if
    next i
    
    if not seguro then
		print color("red") "\nLos procesos est n en un estado inseguro."
        break
    end if
    
	print color("gre") "El proceso est  en un estado seguro."
	print color("whi")"Recursos disponibles: ",
    for i = 1 to r
        print recDispon(i), " ";
    next i
wend
print
end
Retrieved from "https://rosettacode.org/wiki/Banker%27s_algorithm?oldid=365119"
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