二分法模板

其他 C++ 公开

#include <bits/stdc++.h>
using namespace std;
#define ll long long
int n,sum=0,l=15,r=45,mid; 
int main(){
	cin>>n;
	while (l<=r){
		sum++;
		mid = (r+l)/2;
		if (mid == n){
            cout << sum;
			break;
		}else if(mid>n){
			r=mid-1;
		}else{
			l=mid+1;
		}
	}
	
	return 0;
}