/**
 * Created by cshao on 12/23/14.
 */

  。

function getPermutation(arr) {   if (arr.length == 1) {     return [arr];   } 。

  var permutation = [];   for (var i=0; i<arr.length; i++) {     var firstEle = arr[i];     var arrClone = arr.slice(0);     arrClone.splice(i, 1);     var childPermutation = getPermutation(arrClone);     for (var j=0; j<childPermutation.length; j++) {       childPermutation[j].unshift(firstEle);     }     permutation = permutation.concat(childPermutation);   }   return permutation; } 。

var permutation = getPermutation(['a','b','c']); console.dir(permutation),

[ [ 'a', 'b', 'c' ],
  [ 'a', 'c', 'b' ],
  [ 'b', 'a', 'c' ],
  [ 'b', 'c', 'a' ],
  [ 'c', 'a', 'b' ],
  [ 'c', 'b', 'a' ] ]