Minimum Equal Sum of Two Arrays After Replacing Zeros

Leetcode Problem:

• Minimum Equal Sum of Two Arrays After Replacing Zeros

Summary

• Given two arrays of positive integers, replace all 0's with positive integers to make the sum of both arrays equal, and return the minimum equal sum.

Approach

• This solution first calculates the sum of each array and the number of zeros in each array
• It then checks if it's possible to make the sum of both arrays equal by replacing all zeros with positive integers
• If it's possible, it returns the maximum sum of the two arrays, which is the minimum equal sum
• If it's not possible, it returns -1.

Complexity

• O(n), where n is the total number of elements in both arrays.

Explanation

• The solution iterates over each array to calculate the sum and count of zeros
• It then checks if replacing all zeros with positive integers is possible by checking if the sum of one array is greater than the sum of the other array
• If it's possible, it returns the maximum sum of the two arrays
• If it's not possible, it returns -1.

Solution Code:

class Solution {
public:
    long long minSum(vector& nums1, vector& nums2) {
        long long sum1 = 0, sum2 = 0;
        long long zero1 = 0, zero2 = 0;
        for (int i : nums1) {
            sum1 += i;
            if (i == 0) {
                sum1++;
                zero1++;
            }
        }
        for (int i : nums2) {
            sum2 += i;
            if (i == 0) {
                sum2++;
                zero2++;
            }
        }
        if (!zero1 && sum2 > sum1 || !zero2 && sum1 > sum2) {
            return -1;
        }
        return max(sum1, sum2);
    }
};