Sqrt(x)

 1 class Solution
 2 {
 3 public:
 4   int sqrt(int n)
 5   {
 6     int m = n;
 7     if(n == 0 || n == 1)
 8       return n;
 9 
10     int s = 0, e = n, mid = 0;
11     if(e > 46341)
12       e = 46341;
13    
14     while(s < e)
15     {
16       mid = (s + e)/ 2;
17       if(mid * mid < n)
18         s = mid;
19       else if(mid * mid > n)
20         e = mid;
21       else
22         return mid;
23 
24       if(s + 1 == e)
25         return s;
26     }
27   }
28 };