各类排序比较

在写完了各个排序的具体介绍后，现在对各种排序的具体时间做一下比较，形象的看看各个排序的性能(如果对里面具体哪个排序算法不太了解，可以参看博主有关文章)

#include <stdio.h>#include <stdlib.h>#include <iostream>#include <algorithm>#include <time.h>using namespace std;//直接插入排序void insert_sort(int* a, int n){for (int i = 1; i < n; ++i){int j = i - 1;int temp = a[i];while (j >= 0 && a[j] > temp){a[j + 1] = a[j];--j;}a[j + 1] = temp;}}//希尔排序void shell_sort(int* a, int n){int gap = n / 2;while (gap != 0){for (int i = gap; i < n; ++i){int j = i - gap;int temp = a[i];while (j >= 0 && a[j] > temp){a[j + gap] = a[j];j = j - gap;}a[j + gap] = temp;}gap = gap / 2;}}//冒泡排序void bubble_sort(int* a, int n){for (int i = 0; i <= n - 1; ++i){int flag = 1;for (int i = 0; i <= n - i - 1; ++i){if (a[i] > a[i + 1]){int t = a[i];a[i] = a[i + 1];a[i + 1] = t;flag = 0;}}if (flag == 1){break;}}}//选择排序void select_sort(int* a, int n){for (int i = 0; i < n; ++i){int k = i;for (int j = i + 1; j < n; ++j){if (a[k] > a[j]){k = j;}}if (k != i){int t = a[k];a[k] = a[i];a[i] = t;}}}//快速排序void quick_sort(int* a, int left, int right){if (left >= right){return;}int i = left;int j = right;int temp = a[left];while (i < j){while (j > i && temp <= a[j])--j;while (i < j && temp >= a[i])++i;if (i != j){int t = a[i];a[i] = a[j];a[j] = t;}}a[left] = a[i];a[i] = temp;quick_sort(a, left, i - 1);quick_sort(a, i + 1, right);}void swap(int* h, int m, int n){int t;t = h[m];h[m] = h[n];h[n] = t;}//堆排序void siftdown(int* h, int i, int n){int flag = 0, t;while (2 * i <= n && flag == 0){if (h[i] > h[2 * i])t = i;elset = 2 * i;if (2 * i + 1 <= n)if (h[2 * i + 1] > h[t])t = 2 * i + 1;    if (t != i){swap(h, t, i);i = t;//方便继续向下调整}elseflag = 1;}}void creat(int* h, int n){int i;for (i = n / 2; i >= 1; i--)siftdown(h, i, n);}void heap_sort(int* h, int n){while (n > 1)//直到n = 1 即只剩下最后一个数字没有操作，此时也没有必要操作了{swap(h, 1, n);//最大堆的第一个数字最大，把该最大数移到数组的而最后一个数字去    n--;    siftdown(h, 1, n);//把第一个数字重新更新为最大数}}//归并排序void merge(int* a, int low, int mid, int high){    int i = low, j = mid + 1, k = 0;    int *b = (int* )malloc((high - low + 1) * sizeof(int));    while (i <= mid && j <= high)    {        if (a[i] > a[j])        {            b[k] = a[i];            ++i;            ++k;        }        else        {            b[k] = a[j];            ++j;            ++k;        }    }    while (i <= mid)    {        b[k] = a[i];        ++i;        ++k;    }    while (j <= high)    {        b[k] = a[j];        ++j;        ++k;    }    for (i = low, k = 0; i <= high; ++i, ++k)//注意这里i的初值是low而不是0        a[i] = b[k];                         //循环终止条件时i <= high而不是i < high    free(b);}void mergepass(int* a, int length, int n){    int i;    for (i = 0; i + 2 * length - 1 < n; i = i + 2 * length)    {        merge(a, i, i + length - 1, i + 2 * length - 1);    }    if (i + length - 1 < n)        merge(a, i, i + length - 1, n - 1);}void merge_sort(int* a, int n){    for (int length = 1; length < n; length = 2 * length)        mergepass(a, length, n);}//产生随机数int rnd(){return rand() % (1000 - 10 + 1) + 10;}void print(int* a, int n){for (int i = 0; i < n; ++i){printf("%d  ", a[i]);}printf("\n");}int main(){int* a, n;while (~scanf("%d", &n)) //输入需要排列的元素个数{a = (int* )malloc(n * sizeof(int));srand((unsigned)time(NULL));generate_n(a, n, rnd); //用随机数产生数组个数clock_t start, finish; //程序排序开始时间与结束时间start = clock(); //记录下排序前的时间sort(a, a + n);  //这里测试c++里面自带的sort函数finish = clock(); //记录排序结束的时间printf("STL SORT time is: %0.8lf\n", double(finish - start)); //差值即为排序需要时间random_shuffle(a, a + n); //这里必须随机打乱数组元素start = clock();insert_sort(a, n);finish = clock();printf("INSERT SORT time is: %0.8lf\n", double(finish - start));random_shuffle(a, a + n);start = clock();select_sort(a, n);finish = clock();printf("SELECT SORT time is: %0.8lf\n", double(finish - start));random_shuffle(a, a + n);start = clock();bubble_sort(a, n);finish = clock();printf("BUBBLE SORT time is: %0.8lf\n", double(finish - start));random_shuffle(a, a + n);start = clock();shell_sort(a, n);finish = clock();printf("SHELL SORT time is: %0.8lf\n", double(finish - start));random_shuffle(a, a + n);start = clock();quick_sort(a, 0, n - 1);finish = clock();printf("QUICK SORT time is: %0.8lf\n", double(finish - start));random_shuffle(a, a + n);start = clock();creat(a, n - 1);heap_sort(a, n - 1);finish = clock();printf("HEAP SORT time is: %0.8lf\n", double(finish - start));random_shuffle(a, a + n);start = clock();creat(a, n);merge_sort(a, n);finish = clock();printf("MERGE SORT time is: %0.8lf\n", double(finish - start));free(a);}return 0;}