[2039]数据结构上机实验之二分查找

数据结构上机实验之二分查找

题目描述

输入

输出

示例输入

4
1 3 5 8
3

示例输出

YES

#include <stdio.h>

int bin(int *a,int low,int high,int key)

{

int mid;

while(low<=high)

{

mid=(low+high)/2;

if(mid==key)

return mid;

else if(mid>key)

high=mid-1;

else

low=mid+1;

}

return -1;

}

int main()

{

int n,i,key;

while(~scanf("%d",&n))

{

int a
;

for(i=0;i<n;i++)

scanf("%d",&a[i]);

scanf("%d",&key);

if(bin(a,0,n-1,key)!=-1)

printf("YES\n");

else

printf("NO\n");

}

return 0;

}