JS排序算法之归并排序

 1 var group= [1,9,3,5,0,4,2,8];
 2 
 3 
 4 function mergeSort(list) {
 5     var length = list.length;
 6     if(length==1){ //结束条件
 7         return list;
 8         }
 9     var mid = Math.floor(length/2);
10     var left = list.slice(0,mid);
11     var right = list.slice(mid,length);
12     return merge(mergeSort(left),mergeSort(right));//递归
13 };
14 
15 function merge(left,right) {
16     var result = [];
17     var nl = 0;
18     var nr =0;
19     while(nl<left.length && nr<right.length){
20         if(left[nl]<right[nr]){//按从小到大的顺序排列新的组合数组
21             result.push(left[nl++]);//扔进去之后迭代
22         }else{
23             result.push(right[nr++]);
24         }
25 
26     }
27     while(nl<left.length){//剩下的一股脑儿扔进去。
28         result.push(left[nl++]);
29 
30     }
31     while(nr<right.length){
32         result.push(right[nr++]);
33 
34     }
35 
36     return result;
37 }
38 
39 
40 
41 mergeSort(group);