3894. Traffic Signal Color

You are given an integer timer representing the remaining time (in seconds) on a traffic signal.

The signal follows these rules:

• If timer == 0, the signal is "Green"
• If timer == 30, the signal is "Orange"
• If 30 < timer <= 90, the signal is "Red"

Return the current state of the signal. If none of the above conditions are met, return "Invalid".

class Solution {
public:
    string trafficSignal(int timer) {
        return !timer ? "Green" : timer == 30 ? "Orange" : 30 < timer and timer <= 90 ? "Red" : "Invalid";
    }
};