Permutations: Difference between revisions

</pre>

=={{header|Ring}}==

<lang ring>

Another Solution

// Permutations -- Bert Mariani 2020-07-12

// Ask User for number of digits to permutate

? "Enter permutations number : " Give n

n = number(n)

x = 1:n // array

? "Permutations are : "

count = 0

nPermutation(1,n) //===>>> START

? " " // ? = print

? "Exiting of the program... "

? "Enter to Exit : " Give m // To Exit CMD window

//======================

// Returns true only if uniq number on row

Func Place(k,i)

for j=1 to k-1

if x[j] = i // Two numbers in same row

return 0

ok

next

return 1

//======================

Func nPermutation(k, n)

for i = 1 to n

if( Place(k,i)) //===>>> Call

x[k] = i

if(k=n)

See nl

for i= 1 to n

See " "+ x[i]

next

See " "+ (count++)

else

nPermutation(k+1,n) //===>>> Call RECURSION

ok

ok

next

return

</lang>

Output:

<pre>

Enter permutations number :

4

Permutations are :

1 2 3 4

1 2 4 3

1 3 2 4

1 3 4 2

1 4 2 3

1 4 3 2

2 1 3 4

2 1 4 3

2 3 1 4

2 3 4 1

2 4 1 3

2 4 3 1

3 1 2 4

3 1 4 2

3 2 1 4

3 2 4 1

3 4 1 2

3 4 2 1

4 1 2 3

4 1 3 2

4 2 1 3

4 2 3 1

4 3 1 2

4 3 2 1

Exiting of the program...

Enter to Exit :