js的几种排序

转载：http://www.jb51.net/article/81520.htm

一.冒泡排序   平均情况n方，最好n,最差n方

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39

function BubbleSort(array) {   var length = array.length;   for (var i = length - 1; i > 0; i--) { //用于缩小范围     for (var j = 0; j < i; j++) { //在范围内进行冒泡，在此范围内最大的一个将冒到最后面       if (array[j] > array[j+1]) {         var temp = array[j];         array[j] = array[j+1];         array[j+1] = temp;       }     }     console.log(array);     console.log("-----------------------------");   }   return array; }     var arr = [10,9,8,7,7,6,5,11,3]; var result = BubbleSort(arr); console.log(result); /* [ 9, 8, 7, 7, 6, 5, 10, 3, 11 ] ----------------------------- [ 8, 7, 7, 6, 5, 9, 3, 10, 11 ] ----------------------------- [ 7, 7, 6, 5, 8, 3, 9, 10, 11 ] ----------------------------- [ 7, 6, 5, 7, 3, 8, 9, 10, 11 ] ----------------------------- [ 6, 5, 7, 3, 7, 8, 9, 10, 11 ] ----------------------------- [ 5, 6, 3, 7, 7, 8, 9, 10, 11 ] ----------------------------- [ 5, 3, 6, 7, 7, 8, 9, 10, 11 ] ----------------------------- [ 3, 5, 6, 7, 7, 8, 9, 10, 11 ] ----------------------------- [ 3, 5, 6, 7, 7, 8, 9, 10, 11 ] */

二.选择排序  平均n方，最好n方，最差n方

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

function SelectionSort(array) {   var length = array.length;   for (var i = 0; i < length; i++) { //缩小选择的范围     var min = array[i]; //假定范围内第一个为最小值     var index = i; //记录最小值的下标     for (var j = i + 1; j < length; j++) { //在范围内选取最小值       if (array[j] < min) {         min = array[j];         index = j;       }     }     if (index != i) { //把范围内最小值交换到范围内第一个       var temp = array[i];       array[i] = array[index];       array[index] = temp;     }     console.log(array);     console.log("---------------------");   }   return array; }   var arr = [ 1, 10, 100, 90, 65, 5, 4, 10, 2, 4 ]; var result = SelectionSort(arr); console.log(result); /* [ 1, 10, 100, 90, 65, 5, 4, 10, 2, 4 ] --------------------- [ 1, 2, 100, 90, 65, 5, 4, 10, 10, 4 ] --------------------- [ 1, 2, 4, 90, 65, 5, 100, 10, 10, 4 ] --------------------- [ 1, 2, 4, 4, 65, 5, 100, 10, 10, 90 ] --------------------- [ 1, 2, 4, 4, 5, 65, 100, 10, 10, 90 ] --------------------- [ 1, 2, 4, 4, 5, 10, 100, 65, 10, 90 ] --------------------- [ 1, 2, 4, 4, 5, 10, 10, 65, 100, 90 ] --------------------- [ 1, 2, 4, 4, 5, 10, 10, 65, 100, 90 ] --------------------- [ 1, 2, 4, 4, 5, 10, 10, 65, 90, 100 ] --------------------- [ 1, 2, 4, 4, 5, 10, 10, 65, 90, 100 ] --------------------- [ 1, 2, 4, 4, 5, 10, 10, 65, 90, 100 ] */

三.插入排序  平均n方  最好n 最差 n方

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

function InsertionSort(array) {   var length = array.length;   for (var i = 0; i < length - 1; i++) {     //i代表已经排序好的序列最后一项下标     var insert = array[i+1];     var index = i + 1;//记录要被插入的下标     for (var j = i; j >= 0; j--) {       if (insert < array[j]) {         //要插入的项比它小，往后移动         array[j+1] = array[j];         index = j;       }     }     array[index] = insert;     console.log(array);     console.log("-----------------------");   }   return array; }   var arr = [100,90,80,62,80,8,1,2,39]; var result = InsertionSort(arr); console.log(result); /* [ 90, 100, 80, 62, 80, 8, 1, 2, 39 ] ----------------------- [ 80, 90, 100, 62, 80, 8, 1, 2, 39 ] ----------------------- [ 62, 80, 90, 100, 80, 8, 1, 2, 39 ] ----------------------- [ 62, 80, 80, 90, 100, 8, 1, 2, 39 ] ----------------------- [ 8, 62, 80, 80, 90, 100, 1, 2, 39 ] ----------------------- [ 1, 8, 62, 80, 80, 90, 100, 2, 39 ] ----------------------- [ 1, 2, 8, 62, 80, 80, 90, 100, 39 ] ----------------------- [ 1, 2, 8, 39, 62, 80, 80, 90, 100 ] ----------------------- [ 1, 2, 8, 39, 62, 80, 80, 90, 100 ] */

四.希尔排序(shell排序)每一种巧妙算法的本质是利用了一种巧合，shell算法的平均时间是nlog2n说明，他的本质和快速排序是一样的，只不过他的形式不同，不过 有一点相同的，他们都分为2分之一这种思想，不过shell更巧合一点。

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

function ShellSort(array) {   var length = array.length;   var gap = Math.round(length / 2);   while (gap > 0) {     for (var i = gap; i < length; i++) {       var insert = array[i];       var index = i;       for (var j = i; j >= 0; j-=gap) {         if (insert < array[j]) {           array[j+gap] = array[j];           index = j;         }       }       array[index] = insert;     }     console.log(array);     console.log("-----------------------");     gap = Math.round(gap/2 - 0.1);   }   return array; }   var arr = [ 13, 14, 94, 33, 82, 25, 59, 94, 65, 23, 45, 27, 73, 25, 39, 10 ]; var result = ShellSort(arr); console.log(result); /* [ 13, 14, 45, 27, 73, 25, 39, 10, 65, 23, 94, 33, 82, 25, 59, 94 ] ----------------------- [ 13, 14, 39, 10, 65, 23, 45, 27, 73, 25, 59, 33, 82, 25, 94, 94 ] ----------------------- [ 13, 10, 39, 14, 45, 23, 59, 25, 65, 25, 73, 27, 82, 33, 94, 94 ] ----------------------- [ 10, 13, 14, 23, 25, 25, 27, 33, 39, 45, 59, 65, 73, 82, 94, 94 ] ----------------------- [ 10, 13, 14, 23, 25, 25, 27, 33, 39, 45, 59, 65, 73, 82, 94, 94 ] */

五.归并排序

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102

function MergeSort(array) {   var length = array.length;   if (length <= 1) {     return array;   } else {     var num = Math.ceil(length/2);     var left = MergeSort(array.slice(0, num));     var right = MergeSort(array.slice(num, length));     return merge(left, right);   } }   function merge(left, right) {   console.log(left);   console.log(right);   var a = new Array();   while (left.length > 0 && right.length > 0) {     if (left[0] <= right[0]) {       var temp = left.shift();       a.push(temp);     } else {       var temp = right.shift();       a.push(temp);     }   }   if (left.length > 0) {     a = a.concat(left);   }   if (right.length > 0) {     a = a.concat(right);   }   console.log(a);   console.log("-----------------------------");   return a; }   var arr = [ 13, 14, 94, 33, 82, 25, 59, 94, 65, 23, 45, 27, 73, 25, 39, 10 ]; var result = MergeSort(arr); console.log(result); /* [ 13 ] [ 14 ] [ 13, 14 ] ----------------------------- [ 94 ] [ 33 ] [ 33, 94 ] ----------------------------- [ 13, 14 ] [ 33, 94 ] [ 13, 14, 33, 94 ] ----------------------------- [ 82 ] [ 25 ] [ 25, 82 ] ----------------------------- [ 59 ] [ 94 ] [ 59, 94 ] ----------------------------- [ 25, 82 ] [ 59, 94 ] [ 25, 59, 82, 94 ] ----------------------------- [ 13, 14, 33, 94 ] [ 25, 59, 82, 94 ] [ 13, 14, 25, 33, 59, 82, 94, 94 ] ----------------------------- [ 65 ] [ 23 ] [ 23, 65 ] ----------------------------- [ 45 ] [ 27 ] [ 27, 45 ] ----------------------------- [ 23, 65 ] [ 27, 45 ] [ 23, 27, 45, 65 ] ----------------------------- [ 73 ] [ 25 ] [ 25, 73 ] ----------------------------- [ 39 ] [ 10 ] [ 10, 39 ] ----------------------------- [ 25, 73 ] [ 10, 39 ] [ 10, 25, 39, 73 ] ----------------------------- [ 23, 27, 45, 65 ] [ 10, 25, 39, 73 ] [ 10, 23, 25, 27, 39, 45, 65, 73 ] ----------------------------- [ 13, 14, 25, 33, 59, 82, 94, 94 ] [ 10, 23, 25, 27, 39, 45, 65, 73 ] [ 10, 13, 14, 23, 25, 25, 27, 33, 39, 45, 59, 65, 73, 82, 94, 94 ] ----------------------------- [ 10, 13, 14, 23, 25, 25, 27, 33, 39, 45, 59, 65, 73, 82, 94, 94 ] */

六.快速排序  平均情况nlog2n 最好情况nlog2n 最差n2

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

function QuickSort(array) {   var length = array.length;   if (length <= 1) {     return array;   } else {     var smaller = [];     var bigger = [];     var base = [array[0]];     for (var i = 1; i < length; i++) {       if (array[i] <= base[0]) {         smaller.push(array[i]);       } else {         bigger.push(array[i]);       }     }     console.log(smaller.concat(base.concat(bigger)));     console.log("-----------------------");     return QuickSort(smaller).concat(base.concat(QuickSort(bigger)));   } }     var arr = [ 8, 10, 100, 90, 65, 5, 4, 10, 2, 4 ]; var result = QuickSort(arr); console.log(result); /* [ 5, 4, 2, 4, 8, 10, 100, 90, 65, 10 ] ----------------------- [ 4, 2, 4, 5 ] ----------------------- [ 2, 4, 4 ] ----------------------- [ 2, 4 ] ----------------------- [ 10, 10, 100, 90, 65 ] ----------------------- [ 90, 65, 100 ] ----------------------- [ 65, 90 ] ----------------------- [ 2, 4, 4, 5, 8, 10, 10, 65, 90, 100 ] */

这个快速排序和我们通常说的有点不同。

我们可以看百度百科的解释

http://baike.baidu.com/link?url=yTjQ_JjrtfFcBTlMB6lVCt-uDR3QCfLdioGeSos7x5lh2MyvZVrjtNiZLO0wc-ALrTUiLIqjuMK4F6KJWKKHJlJ3kDpJNhYMuaIun9-IM9L8CHM8Qwl9lANRjZD-L-7a6ga9IBrxCcBE4e76d9qbazKsbnWR1wIMucg-SWeBw54u7b2kUziaLoD1QXcS6QIjn5vLZcC8u3y8Kv0EVV1nb2mb7PI8Qtp3exYQKat1oZC

有一篇java的快速排序，感觉比这个还好

代码：

function quickSort(arr, left, right) {
    var len = arr.length,
        partitionIndex,
        left = typeof left != 'number' ? 0 : left,
        right = typeof right != 'number' ? len - 1 : right;

    if (left < right) {
        partitionIndex = partition(arr, left, right);
        quickSort(arr, left, partitionIndex-1);
        quickSort(arr, partitionIndex+1, right);
    }
    return arr;
}

function partition(arr, left ,right) {     //分区操作
    var pivot = left,                      //设定基准值（pivot）
        index = pivot + 1;
    for (var i = index; i <= right; i++) {
        if (arr[i] < arr[pivot]) {
            swap(arr, i, index);
            index++;
        }        
    }
    swap(arr, pivot, index - 1);
    return index-1;
}

function swap(arr, i, j) {
    var temp = arr[i];
    arr[i] = arr[j];
    arr[j] = temp;
}

上面这个快排序有一个奇怪的现象。

我写成 left = left|| 0;这样子就报错了，我没找到原因。以后有时间请人看看吧。 

http://www.cnblogs.com/dushao/p/6004883.html