1644A - Doors and Keys - CodeForces Solution

#include <iostream>
#include <string>

bool checkKey(struct Keys *keys, char door);

struct Keys {
    int red = 0;
    int green = 0;
    int blue = 0;
};

int main(void) {
    int t;  // Amount of test cases;

    std::cin >> t;
    for (int i = 0; i < t; ++i) {
        bool success = true;
        struct Keys keys;
        std::string map;    // Map of the hallway.

        std::cin >> map;
        for (size_t j = 0; j < map.size(); ++j) {
            if (map[j] == 'r')
                keys.red += 1;
            else if (map[j] == 'g')
                keys.green += 1;
            else if (map[j] == 'b')
                keys.blue += 1;
            else
                success = checkKey(&keys, map[j]);

            if (!success)
                break;
        }
        if (success)
            std::cout << "YES" << std::endl;
        else
            std::cout << "NO" << std::endl;
    }
}

bool checkKey(struct Keys *keys, char door) {
    if (door == 'R' && keys->red > 0) {
        keys->red -= 1;
        return true;
    } else if (door == 'G' && keys->green > 0) {
        keys->green -= 1;
        return true;
    } else if (door == 'B' && keys->blue > 0) {
        keys->blue -= 1;
        return true;
    }
    return false;
}