leetcode 日经贴，python code -Sqrt(x)

Sqrt(x)

class Solution:
    # @param x, an integer
    # @return an integer
    def sqrt(self, x):
        if x <= 1:
            return x
        low, high = 1, x
        while low < high:
            mid = (low + high) / 2
            if mid * mid > x:
                high = mid
            else: low = mid + 1
        return low - 1