用 js 实现一个标准的排序算法

一. 冒泡排序

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

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

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 五. 归并排序 六. 快速排序