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3894. Traffic Signal Color

Description

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".

Β 

Example 1:

Input: timer = 60

Output: "Red"

Explanation:

Since timer = 60, and 30 < timer <= 90, the answer is "Red".

Example 2:

Input: timer = 5

Output: "Invalid"

Explanation:

Since timer = 5, it does not satisfy any of the given conditions, the answer is "Invalid".

Β 

Constraints:

  • 0 <= timer <= 1000

Solutions

Solution 1: Simulation

We determine the answer according to the conditions described in the problem and return the corresponding string.

The time complexity is \(O(1)\), and the space complexity is \(O(1)\).

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class Solution:
    def trafficSignal(self, timer: int) -> str:
        if timer == 0:
            return "Green"
        if timer == 30:
            return "Orange"
        if 30 < timer <= 90:
            return "Red"
        return "Invalid"

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class Solution {
    public String trafficSignal(int timer) {
        if (timer == 0) {
            return "Green";
        }
        if (timer == 30) {
            return "Orange";
        }
        if (timer > 30 && timer <= 90) {
            return "Red";
        }
        return "Invalid";
    }
}

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class Solution {
public:
    string trafficSignal(int timer) {
        if (timer == 0) {
            return "Green";
        }
        if (timer == 30) {
            return "Orange";
        }
        if (timer > 30 && timer <= 90) {
            return "Red";
        }
        return "Invalid";
    }
};

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func trafficSignal(timer int) string {
    switch {
    case timer == 0:
        return "Green"
    case timer == 30:
        return "Orange"
    case timer > 30 && timer <= 90:
        return "Red"
    default:
        return "Invalid"
    }
}

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function trafficSignal(timer: number): string {
    if (timer === 0) {
        return 'Green';
    }
    if (timer === 30) {
        return 'Orange';
    }
    if (timer > 30 && timer <= 90) {
        return 'Red';
    }
    return 'Invalid';
}

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