用js写出基本的排序算法
时间: 2024-05-12 09:21:07 浏览: 7
以下是常用的几种排序算法的 JavaScript 实现:
1. 冒泡排序
```js
function bubbleSort(arr) {
var len = arr.length;
for (var i = 0; i < len - 1; i++) {
for (var j = 0; j < len - i - 1; j++) {
if (arr[j] > arr[j + 1]) {
var temp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = temp;
}
}
}
return arr;
}
```
2. 选择排序
```js
function selectionSort(arr) {
var len = arr.length;
for (var i = 0; i < len - 1; i++) {
var minIndex = i;
for (var j = i + 1; j < len; j++) {
if (arr[j] < arr[minIndex]) {
minIndex = j;
}
}
if (minIndex !== i) {
var temp = arr[i];
arr[i] = arr[minIndex];
arr[minIndex] = temp;
}
}
return arr;
}
```
3. 插入排序
```js
function insertionSort(arr) {
var len = arr.length;
for (var i = 1; i < len; i++) {
var temp = arr[i];
var j = i - 1;
while (j >= 0 && arr[j] > temp) {
arr[j + 1] = arr[j];
j--;
}
arr[j + 1] = temp;
}
return arr;
}
```
4. 归并排序
```js
function mergeSort(arr) {
if (arr.length < 2) {
return arr;
}
var middle = Math.floor(arr.length / 2);
var left = arr.slice(0, middle);
var right = arr.slice(middle);
return merge(mergeSort(left), mergeSort(right));
}
function merge(left, right) {
var result = [];
while (left.length && right.length) {
if (left[0] <= right[0]) {
result.push(left.shift());
} else {
result.push(right.shift());
}
}
while (left.length) {
result.push(left.shift());
}
while (right.length) {
result.push(right.shift());
}
return result;
}
```
5. 快速排序
```js
function quickSort(arr) {
if (arr.length < 2) {
return arr;
}
var pivotIndex = Math.floor(Math.random() * arr.length);
var pivot = arr[pivotIndex];
var left = [];
var right = [];
for (var i = 0; i < arr.length; i++) {
if (i === pivotIndex) {
continue;
}
if (arr[i] < pivot) {
left.push(arr[i]);
} else {
right.push(arr[i]);
}
}
return quickSort(left).concat([pivot]).concat(quickSort(right));
}
```