69.x的平方根

69. x 的平方根

int mySqrt(int x){
        long long temp;
        long long left = 1;
        long long right = x;
        long long middle;
        if (x==0)temp=0;
        else if (x==1) temp=1;
        else if(x!=0&&x!=1){
        while(left<=right){
            middle=(left+right)/2;
            if(middle<=x/middle){
                temp=middle;
                left=middle+1;
            }
            else if(middle>x/middle){
                right=middle-1;
            }
        }
        
        }
        return temp;
}

#include<iostream>
#include<vector>
using namespace std;
int main(){
	int temp;
	int n;
	cin>>n;
//	vector<int> x; 
//	for(int i=0;i<n;i++)
//	{
//		x.push_back(i);
//	}
	int left=1;
	int right=n;
	int middle;
//	int target=2;
	
	while(left<=right){
		middle=(left+right)/2;
		if(middle>n/middle){
			right=middle-1;
		}
		else if(middle<=n/middle){  //middle^2<n 
			temp=middle;    //因为2^2<8<2^3  所以直接取这边的middle 
			left=middle+1;
		}

	}
    cout<<temp;

	
	return 0;
}