给出几种排序总结

1.冒泡及其稍微优化

#include<assert.h>void Bubbsort(int a[],int len){assert(a);for (int i = 0; i < len - 1; i++){int tmp = 0;//标志状态for (int j = 0; j < len - i - 1; j++){if (a[j]>a[j + 1]){swap(a[j],a[j+1]);tmp = 1;}}if (tmp == 0)//等于0的话说明上面那个if语句没进去说明已经有序break;}}int main(){int arr[] = { 1, 3, 5, 7, 9, 2, 4, 6, 8,10 };int len = sizeof(arr) / sizeof(arr[0]);Bubbsort(arr,len);system("pause");return 0;}

2.选择排序

(1)   普通代码

#include<assert.h>void SelectSort(int *arr,int len){assert(arr);for (int i = 0; i < len; i++){int k = i;for (int j = i + 1; j < len; j++){if (arr[j]<arr[k]){k = j;}}swap(arr[k],arr[i]);}}int main(){int arr[] = {1,3,5,7,9,2,4,6,8,10};int len = sizeof(arr) / sizeof(arr[0]);SelectSort(arr,len);return 0;}

（2）优化代码

#include<assert.h>void SelectSort(int *arr,int len){assert(arr);for (int i = 0; i < len; i++){int m = len - 1 - i;//放在最后那个元素的下标int min = i;int max = m;for (int j = i + 1; j < len-i; j++)//len-i是避免找过的元素重复被找{if (arr[j]<arr[min]){min = j;}}for (int j = i; j < len-1-i; j++)//len-1-i是最后元素的下标不停往前移动{if (arr[j]>arr[max]){max = j;}}swap(arr[min],arr[i]);if (max == i)swap(arr[min], arr[m]);elseswap(arr[max],arr[m]);}}int main(){int arr[] = {10,3,5,7,9,2,4,6,8,1};int len = sizeof(arr) / sizeof(arr[0]);SelectSort(arr,len);return 0;}

（3）插入排序

#include<assert.h>void SelectSort(int arr[],int len){assert(arr);for (int i = 1; i < len; i++){int end = i - 1;int tmp = arr[i];if (end >= 0){while (arr[end]>tmp)//注意这是tmp比较{arr[end+1] = arr[end];end--;}}arr[end + 1] = tmp;}}int main(){int arr[] = { 1, 3, 5, 7, 9, 2, 4, 6, 8, 10 };int len = sizeof(arr) / sizeof(arr[0]);SelectSort(arr,10);}

（4）堆排序

void AdjustDown(int *a,int n,int parent)//向下调整{assert(a);int child = parent * 2 + 1;while (child < n){if (child + 1<n&&a[child + 1]>a[child]){++child;}if (a[child]>a[parent]){swap(a[child], a[parent]);parent = child;child = parent * 2 + 1;}elsebreak;}}void SortHeap(int *a,int len){int i = (len - 2) / 2;//建大堆for (; i >= 0; i--){AdjustDown(a, len, i);}int end = len - 1;while (end >= 0){swap(a[0],a[end]);AdjustDown(a, end, 0);end--;}}int main(){int arr[] = { 1, 3, 5, 7, 9, 2, 4, 6, 8, 10 };SortHeap(arr, 10);}

（5）快速排序（挖坑法）

void QuickSort(int *a, int l,int r){assert(a);if (l < r){int k = a[l];int i = l;int j = r;while(i<j){while (i<j&&a[j] > k){j--;}if (i < j){a[i] = a[j];i++;}while (i<j&&a[i] <= k){i++;}if (i < j){a[j] = a[i];j--;}}a[i] = k;QuickSort(a, l, i - 1);QuickSort(a, i + 1, r);}}int main(){int a[10] = {1,3,5,7,9,2,4,6,8,10};QuickSort(a,0,9);}

在排序时间复杂度上冒泡，选择，插入都是O（N^2），冒泡与堆排序是O(N*lg(N))