折半查找

#include <stdio.h>#include <stdlib.h>#define NUM 8int a[NUM] = {1, 2, 4, 5 ,8, 9, 10, 15 };int binary_search(int number){int mid, start = 0, end = NUM - 1;while(start <= end){mid = (end + start) / 2;if(a[mid] < number)start = mid + 1;else if(a[mid] > number)end = mid - 1;elsereturn mid;}return -1;}int main(void){printf("%d\n", binary_search(8));return 0;}