769. Max Chunks To Make Sorted

Problem Description
https://leetcode.com/problems/max-chunks-to-make-sorted/description/

class Solution {
public:
    int maxChunksToSorted(vector<int>& arr) {
        int i = 0, sum = 0, answer = 0;

        while (i < arr.size()) {
            sum += (arr[i] - i);
            if (sum == 0) {
                ++answer;
            }
            ++i;
        }

        return answer;
    }
};