快速排序

介绍:

多次比较并交换来完成排序

快速排序的单趟排序思想是

在一个无序数组选出一个key 让key坐标的数都小于key 右边的就大于

image-20230416161027843

递归实现:

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package org.example;

import java.util.Arrays;

public class Main {
public static int[] getPrivot(int[] nums){
privot(nums,0,nums.length-1);
return nums;
}
public static void privot(int[] nums,int left,int right){
if(left > right){
return;
}
int l = left;
int r = right;
int privot = nums[left];
int temp = 0;
while(l < r){
while(privot <= nums[r] && l < r){
r--;
}
while(privot >= nums[l] && l < r){
l++;
}
if(l <= r){
temp = nums[r];
nums[r] = nums[l];
nums[l] = temp;
}
}
nums[left] =nums[l];
nums[l] = privot;
// 递归 比较左边
privot(nums,left,l-1);
// 比较右边
privot(nums,l+1,right);
}

public static void sort(int[] arrays, int left, int right) {
if(left > right) {
return;
}
int l = left;
int r = right;
int pivot = arrays[left];
int temp = 0;
while(l < r) {
while(pivot <= arrays[r] && l < r) {
r--;
}
while(pivot >= arrays[l] && l < r) {
l++;
}
if(l <= r) {
temp = arrays[r];
arrays[r] = arrays[l];
arrays[l] = temp;
}
}
arrays[left] = arrays[l];
arrays[l] = pivot;
sort(arrays, left, l - 1);
sort(arrays, l + 1, right);
}

public static void main(String[] args) {
int[] array = new int[]{19,20,8,7,98,37,40};
sort(array,0,array.length-1);
Arrays.toString(array);
}
}

__END__