Implement int sqrt(int x).

Compute and return the square root of x, where x is guaranteed to be a non-negative integer.

Since the return type is an integer, the decimal digits are truncated and only the integer part of the result is returned.

Example 1:

Input: 4

Output: 2

Example 2:

Input: 8

Output: 2

Explanation: The square root of 8 is 2.82842..., and since the decimal part is truncated, 2 is returned.

代码：

class Solution {public:    int mySqrt(int x) {        int ans = (int)sqrt(x);        return ans;    }}