H面试程序（16）： 简单选择排序
#include<stdio.h>#include<assert.h>void display(int * a, int n) { assert(a);for(int i = 0; i < n; i++){printf("%d,",a[i]);}printf("\n");}void swap(int * a, int * b){ assert(a);assert(b);int temp;temp = *a;*a = *b;*b = temp;}void select_sort(int * a, int n){ assert(a);int i, j,min;for( i = 0; i < n-1 ; i++) //i 0 ~ n-2{min = a[i]; //每次选择一个作为最小值for( j = i; j < n; j++) // j i ~ n-1{if(a[j] < min){ swap(&(a[j]), &(a[i])); }}}}int main(){ int a[10] ={2, 1, 3, 4, 5, 7,2,3, 6, 1};int num = sizeof(a)/sizeof(int);printf("before_sort:");display(a, num);select_sort(a,num);printf("after_sort:");display(a, num);return 0;}
#include <stdio.h>#include <time.h>//交换两个数据void swap(int *a, int *b){int temp;temp = *a;*a = *b;*b = temp;}//显示交换后的数组void display_array( int a[], int n ){ int i; for( i = 0; i < n; i++ ) printf( "%d ", a[i] );}//选择排序void select_sort( int a[], int n ){int i ,j;for(i = 0; i<n-1 ; i++ ) { int min = a[i]; //每次都设定最小的数，i 0 ~ 8for(j =i+1; j <n; j++) // 将a[i]~ a[9]的数于当前最小的数进行比较，如果小于当前最小数就交换{if(a[j] < min){swap(&(a[j]), &(a[i]));}}}}int main(){clock_t start, finish;start = clock(); int n = 10; int a[] = { 2, 1, 3, 4, 5, 7, 6, 8 ,2,4}; printf( "Before sorting: " ); display_array( a, n ); select_sort( a, n ); printf( "After sorting: " ); display_array( a, n ); finish = clock(); printf("\n本次计算一共耗时: %f秒\n\n", (double)(finish-start)/CLOCKS_PER_SEC); return 0;}