Implement Journey Counter and Speeder Detector

Problem Statement

You are provided with a stream of toll booth logs representing vehicles moving through a series of checkpoints. Each log entry is a string in the format: "vehicle_id,checkpoint_id,timestamp_in_seconds".

Your task is to identify "speeding journeys." A journey is defined as a sequence of logs for the same vehicle starting at checkpoint_A and ending at checkpoint_B (where A < B). A speeding violation occurs if the average speed between two consecutive checkpoints in a journey exceeds a given speed_limit. The distance between checkpoint_i and checkpoint_{i+1} is defined as 10 kilometers.

Implement the class SpeedTracker:

class SpeedTracker:
    def __init__(self, speed_limit):
        # Initialize with max speed in km/s
        pass

    def process_logs(self, logs):
        # logs: list of strings
        # Returns a list of vehicle_ids that committed at least one speeding violation
        pass

Constraints

• timestamp is an integer representing seconds since the start of the day.
• checkpoint_id is an integer; a journey is only valid if the vehicle passes checkpoints in strictly increasing numerical order.
• A vehicle might pass multiple checkpoints; calculate speed between every consecutive pair.

Example

Logs: ["V1,1,100", "V1,2,150", "V1,3,170"], speed_limit = 0.15 km/s.

• Journey V1:
  • 1 to 2: Distance 10, Time 50s. Speed = 10/50 = 0.2 km/s (Speeding!)
  • 2 to 3: Distance 10, Time 20s. Speed = 10/20 = 0.5 km/s (Speeding!)
• Output: ["V1"]

Edge Cases

• A vehicle passes a checkpoint with a lower ID than the previous one (invalidates the journey state for that vehicle).
• Multiple journeys for the same vehicle ID (e.g., V1 finishes at 3, then starts again at 1).