Satellite Signal Deduplication

A satellite ground station receives signals in the format: `timestamp sensor_id value`. Due to orbital reflections, some signals are retransmitted. A signal is considered a 'retransmission' if a signal with the exact same `sensor_id` and `value` was received within `T` seconds (inclusive) before the current signal. Count the total number of retransmissions. Input Format: The first line contains an integer T (the time window). Each following line contains an integer timestamp, a string sensor_id, and an integer value. Output Format: An integer representing the total number of retransmission signals. Example: Input: 5 10 S1 100 12 S1 100 20 S1 100 22 S1 100 Output: 2 (Explanation: Signal at 12 is a retransmission of 10 [12-10=2 <= 5]. Signal at 22 is a retransmission of 20 [22-20=2 <= 5]. Signal at 20 is NOT a retransmission of 12 [20-12=8 > 5].)