2263. Make Array Non-decreasing or Non-increasing

You are given a 0-indexed integer array nums. In one operation, you can:

• Choose an index i in the range 0 <= i < nums.length
• Set nums[i] to nums[i] + 1 or nums[i] - 1

Return the minimum number of operations to make nums non-decreasing or non-increasing.

class Solution {
    int helper(vector<int>& A, bool inc) {
        int res = 0, n = A.size();
        priority_queue<int> pq;
        for(int i = inc ? 0 : n - 1; 0 <= i and i < n; i += inc ? 1 : -1) {
            if(!pq.empty() and pq.top() > A[i]) {
                res += pq.top() - A[i]; pq.pop();
                pq.push(A[i]);
            }
            pq.push(A[i]);
        }
        return res;
    }
public:
    int convertArray(vector<int>& nums) {
        return min(helper(nums, true), helper(nums, false));
    }
};