boss直聘|算法 | Java 常见排序算法（纯代码）( 二 )

= temp;

if(!isSort){ return;
else {
isSort = false;

2. 选择排序每次选出最值，再交换到边上；
public void selectSort(int[
nums){ for (int i = 0; i < nums.length-1; i++) { int index = i; int minNum = nums[i
; for (int j = i+1; j < nums.length; j++) { if(nums[j
< minNum){
minNum = nums[j
; index = j;

if(index != i){
nums[index
= nums[i
;
nums[i
= minNum;

3. 插入排序对循环的每个数找到属于自己的位置插入；
public void insertionSort(int[
nums){ for (int i = 1; i < nums.length; i++) { int j = i; int insertNum = nums[i
; while(j-1 >= 0 && nums[j-1
> insertNum){
nums[j
= nums[j-1
;
j--;

nums[j
= insertNum;

4. 快速排序选一个基本值，小于它的放一边，大于它的放另一边；
public void quickSortDfs(int[
nums int left int right){ if(left > right){ return;

int l = left;
int r = right;
int baseNum = nums[left
; while(l < r){ //必须右边先走
while(nums[r
>= baseNum && l < r){
r--;
while(nums[l
<= baseNum && l < r){
l++;

int temp = nums[l
;
nums[l
= nums[r
;
nums[r
= temp;

nums[left
= nums[l
;
nums[l
= baseNum;
quickSortDfs(nums left r-1);
quickSortDfs(nums l+1 right);

5. 归并排序分治算法；
//归public void mergeSortDfs(int[
nums int l int r){ if(l >= r){ return;
int m = (l+r)/2;
mergeSortDfs(nums l m);
mergeSortDfs(nums m+1 r);
merge(nums l m r);
//并private void merge(int[
nums int left int mid int right){ int[
temp = new int[right-left+1
; int l = left; int m = mid+1; int i = 0; while(l <= mid && m <= right){ if(nums[l
< nums[m
){
temp[i++
= nums[l++
;
else {
temp[i++
= nums[m++
;

while(l <= mid){
temp[i++
= nums[l++
;
while(m <= right){
temp[i++
= nums[m++
;

System.arraycopy(temp 0 nums left temp.length);