# LeetCode - 1775. Equal Sum Arrays With Minimum Number of Operations
### 題目網址：https://leetcode.com/problems/equal-sum-arrays-with-minimum-number-of-operations/
###### tags: `LeetCode` `Medium` `貪心演算法（Greedy Algorithm）`

/*
    -LeetCode format-
    Problem: 1775. Equal Sum Arrays With Minimum Number of Operations
    Difficulty: Medium
    
    by Inversionpeter
*/



class Solution {
public:
    int minOperations(vector<int>& nums1, vector<int>& nums2) {
        if (nums1.size() * 6 < nums2.size() || nums2.size() * 6 < nums1.size()) {
            return -1;
        }
        int numbers[6] = {};
        int nowSum1 = accumulate(nums1.begin(), nums1.end(), 0), nowSum2 = accumulate(nums2.begin(), nums2.end(), 0), imbalance = abs(nowSum1 - nowSum2), counts = 0;
        if (nowSum1 < nowSum2) {
            for (int i : nums1) {
                ++numbers[6 - i];
            }
            for (int i : nums2) {
                ++numbers[i - 1];
            }
        }
        else if (nowSum1 > nowSum2) {
            for (int i : nums2) {
                ++numbers[6 - i];
            }
            for (int i : nums1) {
                ++numbers[i - 1];
            }
        }
        for (int i = 5; i >= 1 && imbalance; --i) {
            if (imbalance <= i * numbers[i]) {
                counts += (imbalance + i - 1) / i;
                imbalance = 0;
            }
            else {
                counts += numbers[i];
                imbalance -= i * numbers[i];
            }
        }
        return counts;
    }
};