javascript算法

代码运行环境： nodejs + mochajs
  1 /*
  2  *选择排序
  3  *每次查找数组最小数据
  4  *将最小数据排到左侧   
  5  */
  6 var assert = require('assert');
  7 describe('Array', function() {
  8   describe('#indexOf()', function() {
  9 
 10     var result = [1, 1, 2, 3, 55, 90]
 11 
 12     it('quickSortTest', function() {
 13         var arr1 = [3, 2, 55, 1, 90, 1]
 14         assert.equal(result.toString(), coolSort.quickSort(arr1).toString());
 15     });
 16 
 17     it('bubbleSortTest', function() {
 18         var arr2 = [1, 3, 2, 55, 90, 1]
 19 
 20         assert.equal(result.toString(), coolSort.selectionsSort(arr2).toString());        
 21     })
 22 
 23     it('selectionsSortTest', function() {
 24         var arr3 = [1, 55, 2, 3, 90, 1]
 25 
 26         assert.equal(result.toString(), coolSort.selectionsSort(arr3).toString());        
 27     })
 28   });
 29 });
 30 
 31 var coolSort = (function() {
 32 
 33     function compare(arg1, arg2) {
 34         if(arg1 > arg2) {
 35             return 1;
 36         } else if(arg1 === arg2) {
 37             return 0;
 38         } else {
 39             return -1;
 40         }
 41     }
 42 
 43     function swap(arr, arg1, arg2) {
 44         var temp = arr[arg1];
 45         arr[arg1] = arr[arg2];
 46         arr[arg2] = temp;
 47     }
 48 
 49     this.selectionsSort = function(arr) {
 50         "use strict";
 51         //判断是否是数组
 52         if(Object.prototype.toString.call(arr) !== "[object Array]") return arr;
 53 
 54         var len = arr.length,
 55             min = 0,
 56             j = 0,
 57             temp = 0;
 58 
 59         //判断数组长度
 60         if(len <= 1) return arr;
 61 
 62 
 63         for(var i = 0; i < len -1; i++) {
 64 
 65             min = i;
 66             //查找出最小的一个数据
 67             for(j = i + 1; j < len; j++) {
 68                 if(compare(arr[min], arr[j]) === 1)
 69                     min = j;
 70             }
 71             //如果i不是最小的数据，将i与最小数据进行交换
 72             if(min !== i) swap(arr, min, i)
 73 
 74         }
 75 
 76         return arr;        
 77     }
 78 
 79     this.quickSort = function(arr) {
 80         "use strict";
 81         if(arr.length <= 1) return arr;
 82 
 83         var pivotIndex = Math.floor((arr.length / 2));
 84         var pivot = arr.splice(pivotIndex, 1);
 85 
 86         var left = [];
 87         var right = [];
 88 
 89         for(var i =0; i < arr.length; i++) {
 90             if(arr[i] < pivot) {
 91                 left.push(arr[i]);
 92             } else {
 93                 right.push(arr[i]);
 94             }
 95         }
 96 
 97         return quickSort(left).concat(pivot, quickSort(right))
 98     }
 99 
100     this.bubbleSort = function (arr) {
101         "use strict";
102         var temp = 0,
103             len = arr.length,
104             j = 0;
105         for(var i =0; i < len - 1; i++) {
106             for(j = 0; j < len - i - 1; j++) {
107                 if(compare(arr[j], arr[j + 1]) === 1 ) {
108                     swap(arr, j , j + 1);
109                 }
110             }
111         }
112         return arr;
113     }
114 
115     return this;
116 })()