1 var allResult = [];
 2 
 3 function queue(arr, size, result){
 4   //first call
 5   if(result == undefined){
 6     result = [];
 7     if(size > arr.length){
 8       return;
 9     }
10   }
11 
12   if(result.length == size){
13     store(result);
14   }
15 
16   for(var i =0 ;i < arr.length; i++){
17     var newArr = [].concat(arr),
18         curItem = newArr.splice(i,1);
19     arguments.callee(newArr, size, [].concat(result,curItem));
20   }
21 }
22 
23 
24 function choose(arr, size, result ){
25   //first call
26   if(result == undefined){
27     result = [];
28     console.log(‘choose ‘+ size + ‘ items from: ‘ + arr);
29   }
30   if(size > arr.length){
31     return;
32   }
33 
34   if(size == arr.length){
35     store([].concat(result, arr));
36   }else{
37     for(var i =0 ; i < arr.length; i++){
38       var newResult = [].concat(result);
39       newResult.push(arr[i]);
40 
41       if(size == 1){
42         store(newResult);
43       }else{
44         var newArr = [].concat(arr);
45         newArr.splice(0, i +　1);
46         arguments.callee(newArr, size - 1, newResult);
47       }
48     }
49   }
50 }
51 
52 function store(result){
53   console.log(result);
54   allResult.push(result);
55 }
56 
57 
58 var arr = [‘姬光‘,‘王子‘, ‘三桂‘,‘科长‘,‘猫哥‘];
59 
60 choose(arr, 4);
61 //queue(arr, arr.length);
62 
63 console.log(‘The number of result sets: ‘ + allResult.length);