编辑代码

#include<stdio.h>
#define N 7

int Search(int a[],int low,int high,int key){
	int mid;
	if(low>high){
		return -1;
	}else{
		mid = (low+high)/2;
		if(a[mid]==key){
			return mid;
		}else if(a[mid]<key){//中间位置的关键字小于要查找的关键字
			return Search(a,mid+1,high,key);
		}else{//中间位置的关键字大于要查找的关键字
			return Search(a,low,mid-1,key);
		}
	}
}


int main(void)
{
	int a[N]={2,5,6,9,17,23,54};
	int i,key;
	printf("请输入你要查找的值:");
	scanf("%d",&key);
	i = Search(a,0,N-1,key);
	printf("%d",i);
	return 0;
}