代码

#include<bits/stdc++.h>
using namespace std;
int binary_search(const unsigned *a, int n, unsigned x)
{
	int l=1,r=n,ans=0;
while(l<=r){
int mid=(l+r)>>1;
if(a[mid]==x){
return mid;
}if(a[mid]<x)l=mid+1;
else r=mid-1;
}
}

评测结果