Java排序

Java 常用排序方法（直接可用）

1. 数组自带排序（最简单）

import java.util.Arrays;

public class Main {

public static void main(String\[\] args) {

int\[\] arr = {5, 2, 9, 1, 5, 6};

// 升序排序

Arrays.sort(arr);

System.out.println(Arrays.toString(arr));

}

}

2. 集合排序（List）

import java.util.ArrayList;

import java.util.Collections;

public class Main {

public static void main(String\[\] args) {

ArrayList<Integer> list = new ArrayList<>();

list.add(3);

list.add(1);

list.add(4);

Collections.sort(list);

System.out.println(list);

}

}

3. 冒泡排序（手写基础）

public static void bubbleSort(int\[\] arr) {

int n = arr.length;

for (int i = 0; i < n-1; i++) {

for (int j = 0; j < n-i-1; j++) {

if (arrj > arrj+1) {

int temp = arrj;

arrj = arrj+1;

arrj+1 = temp;

}

}

}

}

4. 选择排序

public static void selectionSort(int\[\] arr) {

int n = arr.length;

for (int i = 0; i < n-1; i++) {

int min = i;

for (int j = i+1; j < n; j++) {

if (arrj < arrmin) min = j;

}

int temp = arrmin;

arrmin = arri;

arri = temp;

}

}

5. 插入排序

public static void insertionSort(int\[\] arr) {

int n = arr.length;

for (int i = 1; i < n; i++) {

int key = arri;

int j = i - 1;

while (j >= 0 && arrj > key) {

arrj+1 = arrj;

j--;

}

arrj+1 = key;

}

}

6. 快速排序（常用高效）

public static void quickSort(int\[\] arr, int left, int right) {

if (left >= right) return;

int i = left, j = right, pivot = arrleft;

while (i < j) {

while (i < j && arrj >= pivot) j--;

arri = arrj;

while (i < j && arri <= pivot) i++;

arrj = arri;

}

arri = pivot;

quickSort(arr, left, i-1);

quickSort(arr, i+1, right);

}