Code Golf: Conway's Game of Life

Answer 1

perl, 127 129 135 chars

Managed to strip off a couple more characters...

$/=pop;@b=split'',<>;map{$n=-1;@b=map{++$n;/
/?$_:($t=grep/X/,@b[map{$n+$_,$n-$_}1,80..82])==3|$t+/X/==3?X:'.'}@b}1..$/;print@b

Answer 2

Ruby 1.9 - 189 178 159 155 153 chars

f,n=$*
c=IO.read f
n.to_i.times{i=0;c=c.chars.map{|v|i+=1
v<?.?v:('...X'+v)[[83,2,-79].map{|j|c[i-j,3]}.to_s.count ?X]||?.}*''}
File.new('out.txt',?w)<<c

Edit: Handles newlines with 4 chars less.
Can remove 7 more (v<?.?v:) if you allow it to clobber newlines when the live cells reach the edges.

Answer 3

Haskell - 284 272 232 chars

import System
main=do f:n:_<-getArgs;s<-readFile f;writeFile"out.txt"$t s$read n
p '\n'_='\n'
p 'X'2='X'
p _ 3='X'
p _ _='.'
t r 0=r
t r n=t[p(r!!m)$sum[1|d<-1:[80..82],s<-[1,-1],-m<=d*s,m+d*s<3240,'X'==r!!(m+d*s)]|m<-[0..3239]]$n-1

Answer 4

RUST - 469 characters Don't know if I should post this here, (this post is 3 years old) but anyway, my try on this, in rust (0.9):

use std::io::fs::File;fn main(){
let mut c=File::open(&Path::new(std::os::args()[1])).read_to_end();
for _ in range(0,from_str::<int>(std::os::args()[2]).unwrap()){
let mut b=c.clone();for y in range(0,40){for x in range(0,80){let mut s=0;
for z in range(x-1,x+2){for t in range(y-1,y+2){
if z>=0&&t>=0&&z<80&&t<40&&(x !=z||y !=t)&&c[t*81+z]==88u8{s +=1;}}}
b[y*81+x]=if s==3||(s==2&&c[y*81+x]==88u8){88u8} else {46u8};}}c = b;}
File::create(&Path::new("out.txt")).write(c);}

For people interested, here is the code before some agressive golfing:

use std::io::fs::File;
fn main() {
    let f = std::os::args()[1];
    let mut c = File::open(&Path::new(f)).read_to_end();    
    let n = from_str::<int>(std::os::args()[2]).unwrap();   
    for _ in range(0,n)
    {
        let mut new = c.clone();
        for y in range(0,40) {
            for x in range(0,80) {
                let mut sum = 0;
                for xx in range(x-1,x+2){
                    for yy in range(y-1,y+2) {
                        if xx >= 0 && yy >= 0 && xx <80 && yy <40 && (x != xx || y != yy) && c[yy*81+xx] == 88u8
                        { sum = sum + 1; }
                    }
                }
                new[y*81+x] = if sum == 3 || (sum == 2 && c[y*81+x] == 88u8) {88u8} else {46u8};                    
            }
        }
        c = new;
    }
    File::create(&Path::new("out.txt")).write(c);
}

Answer 5

Javascript/Node.js - 233 236 characters

a=process.argv
f=require('fs')
m=46
t=f.readFileSync(a[2])
while(a[3]--)t=[].map.call(t,function(c,i){for(n=g=0;e=[-82,-81,-80,-1,1,80,81,82][g++];)t[i+e]>m&&n++
return c<m?c:c==m&&n==3||c>m&&n>1&&n<4?88:m})
f.writeFile('out.txt',t)

Answer 6

c++ - 492 454 386

---

my first code golf ;)

#include<fstream>
#define B(i,j)(b[i][j]=='X')
int main(int i,char**v){for(int n=0;n<atoi(v[2]);++n){std::ifstream f(v[1]);v[1]="out.txt";char b[40][83];for(i=0;i<40;++i)f.getline(b[i],83);std::ofstream g("out.txt");g<<b[0]<<'\n';for(i=1;i<39;++i){g<<'.';for(int j=1;j<79;++j){int k=B(i-1,j)+B(i+1,j)+B(i,j-1)+B(i,j+1)+B(i-1,j-1)+B(i+1,j+1)+B(i+1,j-1)+B(i-1,j+1);(B(i,j)&&(k<2||k>3))?g<<'.':(!B(i,j)&&k==3)?g<<'X':g<<b[i][j];}g<<".\n";}g<<b[0]<<'\n';}}

A somewhat revised version, replacing some of the logic with a table lookup+a few other minor tricks:

#include<fstream>
#define B(x,y)(b[i+x][j+y]=='X')
int main(int i,char**v){for(int n=0;n<atoi(v[2]);++n){std::ifstream f(v[1]);*v="out.txt";char b[40][83], O[]="...X.....";for(i=0;i<40;++i)f>>b[i];std::ofstream g(*v);g<<b[0]<<'\n';for(i=1;i<39;++i){g<<'.';for(int j=1;j<79;++j){O[2]=b[i][j];g<<O[B(-1,0)+B(1,0)+B(0,-1)+B(0,1)+B(-1,-1)+B(1,1)+B(1,-1)+B(-1,1)];}g<<".\n";}g<<b[0]<<'\n';}}