2485-find-the-pivot-integer

DevGod

Vtuber

Caution

DevGod needs to write an editorial for this problem!

js

/**
 * @param {number} n
 * @return {number}
 */
var pivotInteger = function(n) {
    if(n==1){return 1;}
    let sum = (n+1)*(n/2);
    let temp = 0;

    for(let I = 0; I<n; I++){
        sum += -I;
        if(sum == temp){
            return I;
        }
        temp += I;
    }

    return -1;
};

py

class Solution:
    def pivotInteger(self,n):
        if n == 1:
            return 1

        sum_total = (n + 1) * (n // 2)
        temp = 0

        for i in range(n):
            sum_total -= i
            if sum_total == temp:
                return i
            temp += i

        return -1