enum class

Lab C++ Intermediate 20 points

Define enum class Light { Red, Green, Yellow }; with a function next(Light) using a switch, and toString. Read a starting colour and a number of steps; print each state.

Input

Line 1: Red, Green or Yellow. Line 2: steps.

Output

One line per step.

Example

Input

Red
4

Output

Green
Yellow
Red
Green

Sample input available Sample output available

Editor

C++

Hints

enum class values are scoped: Light::Red.

They don't convert to int implicitly.

Solution explanation

Scoped enums avoid name clashes and accidental integer arithmetic.

Show solution

#include <iostream>
#include <string>
using namespace std;

enum class Light { Red, Green, Yellow };

Light next(Light l) {
    switch (l) {
        case Light::Red: return Light::Green;
        case Light::Green: return Light::Yellow;
        default: return Light::Red;
    }
}

string toString(Light l) {
    switch (l) {
        case Light::Red: return "Red";
        case Light::Green: return "Green";
        default: return "Yellow";
    }
}

int main() {
    string start;
    int steps;
    cin >> start >> steps;
    Light l = start == "Red" ? Light::Red : start == "Green" ? Light::Green : Light::Yellow;
    for (int i = 0; i < steps; i++) {
        l = next(l);
        cout << toString(l) << "\n";
    }
    return 0;
}

Output

Answer