Given a positive integer n, find the pivot integer x such that:
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.
Input: n = 1
Output: 1
Explanation: 1 is the pivot integer since: 1 = 1.
Example 3
Input: n = 4
Output: -1
Explanation: It can be proved that no such integer exist.
Constraints
1 <= n <= 1000
2485. Find the Pivot Integer
Easy
10 Points
Math
Prefix Sum
Given a positive integer n, find the pivot integer x such that:
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.