#include <stdio.h>
#include <stdlib.h>
#define MAX 20int intcmp(const void *v1, const void *v2);int main(void){int arr[MAX], count, key, *ptr;//提示用户输入一些整数 printf("Enter %d integer values; press Enter each.\n", MAX);for(count = 0; count < MAX; count++){scanf("%d", &arr[count]);}puts("Press Enter to sort the values.");getc(stdin);//将数组中的元素按升序排列qsort(arr, MAX, sizeof(arr[0]), intcmp);//显示已排列的数组元素for(count = 0; count < MAX; count++){printf("\narr[%d] = %d.", count, arr[count]);}puts("\nPress Enter to continue.");getc(stdin);//输入要查找的值printf("Enter a value to search for: ");scanf("%d", &key);//执行查找ptr = (int *)bsearch(&key, arr, MAX, sizeof(arr[0]), intcmp);if(ptr != NULL){printf("%d found at arr[%d].", key, (ptr - arr));} else {printf("%d not found.", key);}return 0;
}int intcmp(const void *v1, const void *v2){return (*(int *)v1 - *(int *)v2);
}/*用qsort（）和bsearch（）对字符串进行排序和查找*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 20int comp(const void *s1, const void *s2);int main(void){char *data[MAX], buf[80], *ptr, *key, **key1;int count;//输入单词或短语printf("Enter %d words or phrases, pressing Enter after each.\n", MAX);for(count = 0; count < MAX; count++){printf("Word %d: ", count + 1);gets(buf);data[count] = malloc(strlen(buf)+1);strcpy(data[count], buf);} //排列字符串（实际上是排列指针）qsort(data, MAX, sizeof(data[0]), comp);//显示已排列的字符串for(count = 0; count < MAX; count++){printf("\n%d: %s", count + 1, data[count]);}//提示用户输入待查找的单词printf("\n\nEnter a search key: ");gets(buf);// Perform the search. First, make key1 a pointer// to the pointer to the search key.key = buf;key1 = &key;ptr = bsearch(key1, data, MAX, sizeof(data[0]), comp);if(ptr != NULL){printf("%s found.\n", buf);} else {printf("%s not found.\n", buf);}return (0);
}
int comp(const void *s1, const void *s2){return (strcmp(*(char **)s1, *(char **)s2));
}