js 排序算法
2018-03-23 本文已影响0人
蘑菇酱960903
/*生成一个[min,max)的随机数*/
function randomNum1(min, max) {
return Math.floor(Math.random()*(max - min + 1) + min);
}
/*生成array数组*/
function array(min,max,count) {
var i = 1, arr = [];
while (i++ <= count) {
arr.push(randomNum1(min,max));
}
return arr;
}
/*冒泡排序*/
function bubbleSort(arr) {
var len = arr.length, temp;
for (var i = 0; i < len-1; i++) {
for (var j = i+1; j < len; j++){
if (arr[i] > arr[j]) {
temp = arr[j];
arr[j] = arr[i];
arr[i] = temp;
}
}
}
return arr;
}
/*选择排序*/
function selectSort(arr) {
var len = arr.length, temp, flag;
for (var i = 0; i < len-1; i++) {
flag = i;
for (var j = i+1; j < len; j++) {
if (arr[flag] > arr[j]) {
flag = j;
}
}
if (flag !== i) {
temp = arr[flag];
arr[flag] = arr[i];
arr[i] = temp;
}
}
return arr;
}
/*插入排序*/
function insertSort(arr) {
var len = arr.length, temp;
for (var i = 1; i < len; i++) {
temp = arr[i];
for (var j = i; j > 0; j--) {
if (temp < arr[j-1]) {
arr[j] = arr[j-1];
arr[j-1] = temp;
}
}
}
return arr;
}
/*二分排序*/
function sort(arr) {
var len = arr.length;
for (var i = 1; i < len; i++) {
var low, high, mid;
low = 0;
high = i-1;
var temp = arr[i];
while (low <= high) {
mid = Math.floor((low + high) / 2);
if (arr[mid] > temp) {
high = mid - 1;
} else {
low = mid + 1;
}
}
for (var j = i - 1; j > high; j--) {
arr[j + 1] = arr[j];
}
arr[high + 1] = temp;
}
return arr;
}
/*快速排序*/
/*
利用递归方法
先选出temp = arr[low],low指向最小值,high指向最大值
不断让arr[low] arr[high] 与temp比较,将数组分成两个部分,左边为都小于temp的数,右边为都大于temp的数,
再继续递归,先把左边小于temp再一次操作,选出low,temp,high…… 然后右边操作
*/
function quickSort(arr, low, high) {
if (low < high) {
var pre = Partition(arr, low, high);
quickSort(arr, low, pre-1);
quickSort(arr, pre+1, high);
}
}
function Partition(arr, low, high) {
var temp = arr[low];
while (low < high) {
while (low < high && arr[high] >= temp) {
high--;
}
if (low < high) {
arr[low++] = arr[high];
}
while (low < high && arr[low] <= temp) {
low++;
}
if (low < high) {
arr[high--] = arr[low];
}
}
arr[low] = temp;
return low;
}