Elementary cellular automaton: Difference between revisions

=={{header|Go}}==

<lang go>package main

import (

"fmt"

"math/big"

"math/rand"

"strings"

)

func main() {

const cells = 20

const generations = 9

fmt.Println("Single 1, rule 90:")

a := big.NewInt(1)

a.Lsh(a, cells/2)

elem(90, cells, generations, a)

fmt.Println("Random intial state, rule 30:")

a = big.NewInt(1)

a.Rand(rand.New(rand.NewSource(3)), a.Lsh(a, cells))

elem(30, cells, generations, a)

}

func elem(rule uint, cells, generations int, a *big.Int) {

output := func() {

fmt.Println(strings.Replace(strings.Replace(

fmt.Sprintf("%0*b", cells, a), "0", " ", -1), "1", "#", -1))

}

output()

a1 := new(big.Int)

set := func(cell int, k uint) {

a1.SetBit(a1, cell, rule>>k&1)

}

last := cells - 1

for r := 0; r < generations; r++ {

k := a.Bit(last) | a.Bit(0)<<1 | a.Bit(1)<<2

set(0, k)

for c := 1; c < last; c++ {

k = k>>1 | a.Bit(c+1)<<2

set(c, k)

}

set(last, k>>1|a.Bit(0)<<2)

a, a1 = a1, a

output()

}

}</lang>

{{out}}

<pre>

Single 1, rule 90:

#

# #

# #

# # # #

# #

# # # #

# # # #

# # # # # # # #

# #

# # # #

Random intial state, rule 30:

# # # #### #

## ## #### # ##

# # # # ### ##

######### ## # # #

# ## ## #

# ##### # #

# ## ######

## ## # ##

## # ## #### #

# #### ### ## #

</pre>