选择排序

#include <stdio.h>void selectsort(int num[],int count){int j;int key;int i = 0;for(i; i < count-1;i++){j = i+1;for(j; j<count;j++){if(num[i] >num[j]){key = num[j];num[j] = num[i];num[i] = key;}}}}

文件名：selection_sort.c

#include <stdio.h>#include <stdlib.h>#include <sys/time.h>#define MAXNUM 1000000void selectsort(int [],int);int main(){int i;int j;int num[MAXNUM];struct timeval time1;struct timeval time2;long int runtime;printf("Please enter a Integer:/n");scanf("%d",&i);printf("i is %d/n", i);if(i > MAXNUM){printf("You should input small number/n");exit(0);}printf("1");for(j = 0; j < i;j++){num[j] = rand();printf("%d/n", num[j]);}printf("running/n");if(gettimeofday(&time1,NULL) == -1){printf("you get time time1 error/n"); exit(0);}selectsort(num,i);if(gettimeofday(&time2,NULL) == -1){printf("you get time time2 error/n");exit(0);}for(j = 0; j < i ; j++){printf("%d/t", num[j]);}runtime = (time2.tv_sec - time1.tv_sec)*1000000 +(time2.tv_usec - time1.tv_usec);printf("The running is %ld microseconds/n", runtime);return 0;}

文件名：test_selectsort.c

编译命令 :gcc -o test_selectsort test_selectsort.c selection_sort.c

输入：100

运行时间：96 microseconds

输入：1000

运行时间：10639 microseconds

输入  :  10000

运行时间 :  534384 microseconds

输入  :  100000

运行时间 :  53493030 microseconds