2335. Minimum Amount of Time to Fill Cups

You have a water dispenser that can dispense cold, warm, and hot water. Every second, you can either fill up 2 cups with different types of water, or 1 cup of any type of water.

You are given a 0-indexed integer array amount of length 3 where amount[0], amount[1], and amount[2] denote the number of cold, warm, and hot water cups you need to fill respectively. Return the minimum number of seconds needed to fill up all the cups.

class Solution {
public:
    int fillCups(vector<int>& A) {
        int res = 0;
        while(!A.empty()) {
            sort(rbegin(A), rend(A));
            while(!A.empty() and A.back() == 0) A.pop_back();
            if(A.size() == 1) {
                res += A[0];
                A.pop_back();
            } else if(A.size() == 2) {
                res += A[1];
                A[0] -= A[1];
                A.pop_back();
            } else if(A.size() == 3) {
                res += 1;
                A[0] -=1;
                A[1] -= 1;
            }
        }
        return res;
    }
};