Generate n-permutations

perm.js

var allPerms = [];

function permutation(list, ret)
{
  if (list.length == 0) {
    allPerms.push(ret);  // return the result
    return;
  }
  
  for (var i = 0; i < list.length; i++) {
    var x = list.splice(i, 1);  // delete the i_th element
    ret.push(x);
    perm(list, ret);  // recursively call with one less element
    ret.pop();
    list.splice(i, 0, x);  // put back the element
  }
}