Sqrt(x).py

Given a non-negative integer x, return the square root of x rounded down to the nearest integer. The returned integer should be non-negative as well.

You must not use any built-in exponent function or operator.

For example, do not use pow(x, 0.5) in c++ or x ** 0.5 in python.
 

Example 1:

Input: x = 4
Output: 2
Explanation: The square root of 4 is 2, so we return 2.
Example 2:

Input: x = 8
Output: 2
Explanation: The square root of 8 is 2.82842..., and since we round it down to the nearest integer, 2 is returned.




#my solution(python3):
class Solution:
    def mySqrt(self, x: int) -> int:
        if x < 2:
            return x
        l, r = 0, x
        while abs(r-l) != 1:
            mid = (l + r) // 2
            product = mid * mid
            if product == x:
                return mid
            elif product > x:
                r = mid
            else:
                l = mid
        return l