# 2485. Find the Pivot Integer from math import sqrt """ given a positive integer 'n', find the pivot integer 'x' such that the sum of all elements between 1 and 'x' inclusively equals the sum of all elements between 'x' and 'n' inclusively. return the pivot integer 'x'. if no such integer exists, return -1. it is guaranteed that there will be at most one pivot index for the given input. """ class Solution(object): def pivotInteger(self, n): """ :type n: int :rtype: int """ tmp = (n * n + n) // 2 sqr = int(sqrt(tmp)) if sqr * sqr == tmp: return sqr return -1 if __name__ == "__main__": obj = Solution() print(obj.pivotInteger(8)) print(obj.pivotInteger(1)) print(obj.pivotInteger(4))