Finding the root of an integer by dichotomy

A daily topic ing, Today is a day easy topic 69. Sqrt(x)
Solution 1 （ Violence law ）：

class Solution {
    
public:
    int mySqrt(int x) {
    
        for(int i=1;i<=x/2+1;i++){
    
            if(i<=x/i&&(i+1)>x/(i+1)){
    
                return i;
            }
        }
        return 0;
    }
};

Solution 2 （ Dichotomy ）：

class Solution {
    
public:
    int mySqrt(int x) {
    
        if(x<=1){
    
            return x;
        }
        int left=1,right=x/2;
        while(left<=right){
    
            int mid=(right+left)/2;
            if(mid>x/mid){
    
                right=mid-1;
            }
            else if(mid<x/mid){
    
                left=mid+1;
            }
            else{
    
                return mid;
            }
        }
        return right;
    }
};