matrixElementsum.cpp

/**
        After becoming famous, the CodeBots decided to move into a new 
        uilding together. Each of the rooms has a different cost, and 
        ome of them are free, but there's a rumour that all the free 
        ooms are haunted! Since the CodeBots are quite superstitious, 
        hey refuse to stay in any of the free rooms, or any of the 
        ooms below any of the free rooms.
        
        Given matrix, a rectangular matrix of integers, where each 
        alue represents the cost of the room, your task is to return 
        he total sum of all rooms that are suitable for the CodeBots 
        ie: add up all the values that don't appear below a 0).
    */
#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

   
int solution(vector<vector<int>> matrix) {
    vector<int> indices;
    auto total = 0;
    
    for (auto i = 0; i < matrix.size(); i++)
    {
        const auto ht = matrix[i].size();
        
        for (auto j = 0; j < ht; j++)
        {
            auto res = find(indices.begin(), indices.end(), j);
            const auto elem = matrix[i][j];
            
            if (elem == 0 || res != indices.end())
            {
                indices.push_back(j);
                continue;
            }
            else if (res == indices.end())
            {
                total += elem;
            }
        }
    }
    return total;
}



int main()
{
    vector<vector<int>> m = {{0, 1, 1, 2},
                             {0, 5, 0, 0},
                             {2, 0, 3, 3}};

    cout << solution(m) << '\n';    // 9
}