Problem URL: Find missing observations

We are given an array of n integers. We are also given m missing values. We need to find all the possible values that can be assigned to the missing values such that the sum of the array becomes totalSum.

We will calculate the sum of the array. Then, we will calculate the sum of the missing values. We will subtract the sum of the missing values from the totalSum to get the sum of the array. Then, we will divide the sum of the array by n+m to get the value of each missing value. We will check if the value of each missing value is in the range [1, 6]. If it is, we will add it to the result.

class Solution:
    def missingRolls(self, rolls: List[int], mean: int, n: int) -> List[int]:
        numRolls = len(rolls)
        curSum = sum(rolls)
        missingSum = mean * (n + numRolls) - curSum

        if missingSum < n or missingSum > 6*n: 
            return []

        part, rem = divmod(missingSum, n)
        ans = [part] * n
        for i in range(rem):
            ans[i] += 1
        return ans

Time Complexity: O(m+n)
Space Complexity: O(1)