leetcode-Sqrt(x)

Implement int sqrt(int x).

Compute and return the square root of x.

class Solution {public:    int sqrt(int x) {        if(x <= 1) return x;          int l = 0;           int r = x;          while (l <= r)          {              int m = l+(r-l)/2;              int now = x/m;//avoid overflow              if (now < m)                  r = m-1;              else if(now > m)                  l = m+1;              else return m;          }          return r;//the small one is the answer      }};