Find Missing Observations

/*
2028. Find Missing Observations
https://leetcode.com/problems/find-missing-observations/
*/

class Solution {
    public int[] missingRolls(int[] rolls, int mean, int n) {
        int m = rolls.length;
        int totalSum = mean * (n + m);
        int observedSum = 0;
        
        for (int roll : rolls) {
            observedSum += roll;
        }
        
        int missingSum = totalSum - observedSum;
        
        if (missingSum < n || missingSum > 6 * n) {
            return new int[0];
        }
        
        int base = missingSum / n;
        int remainder = missingSum % n;
        
        int[] result = new int[n];
        for (int i = 0; i < n; i++) {
            result[i] = base + (i < remainder ? 1 : 0);
        }
        
        return result;
    }
}

/*
Example 1:

Input: rolls = [3,2,4,3], mean = 4, n = 2
Output: [6,6]
Explanation: The mean of all n + m rolls is (3 + 2 + 4 + 3 + 6 + 6) / 6 = 4.

Example 2:

Input: rolls = [1,5,6], mean = 3, n = 4
Output: [2,3,2,2]
Explanation: The mean of all n + m rolls is (1 + 5 + 6 + 2 + 3 + 2 + 2) / 7 = 3.
*/