1 from collections import Counter
 2 
 3 def isBot(input_str, threshold):
 4     # Parse the input string into a list of IPs
 5     # We ignore the timestamp for this specific part as per the example
 6     lines = input_str.strip().split('\n')
 7     ips = [line.split(', ')[1] for line in lines if line]
 8     
 9     # Count occurrences
10     counts = Counter(ips)
11     
12     # Filter by threshold
13     bots = [ip for ip, count in counts.items() if count >= threshold]
14     
15     # Sort or format as needed (returning list for clarity)
16     return sorted(bots)
17 
18 # Testing
19 data = """
20 1, ip1
21 1, ip2
22 1, ip1
23 4, ip1
24 4, ip2
25 5, ip3
26 """
27 
28 print(f"Threshold 3: {isBot(data, 3)}") # ['ip1']
29 print(f"Threshold 2: {isBot(data, 2)}") # ['ip1', 'ip2']
30 print(f"Threshold 1: {isBot(data, 1)}") # ['ip1', 'ip2', 'ip3']

 1 from collections import deque, defaultdict
 2 
 3 class CheckBot:
 4     def __init__(self, threshold, window_size):
 5         self.threshold = threshold
 6         self.window_size = window_size
 7         # defaultdict automatically creates a deque for any new IP key
 8         self.history = defaultdict(deque)
 9 
10     def is_bot(self, timestamp, ip):
11         # 1. Add current timestamp (auto-creates deque if ip is new)
12         self.history[ip].append(timestamp)
13         
14         # 2. Remove timestamps that have fallen out of the sliding window
15         # Logic: Window includes [timestamp - window_size + 1, timestamp]
16         # Example: timestamp 4, window 3 -> valid range is [2, 3, 4]. 
17         # Anything <= (4 - 3) i.e. 1 is expired.
18         while self.history[ip] and self.history[ip][0] <= timestamp - self.window_size:
19             self.history[ip].popleft()
20             
21         # 3. Check if count meets or exceeds threshold
22         return len(self.history[ip]) >= self.threshold
23 
24 # --- Example Usage ---
25 cb = CheckBot(threshold=3, window_size=3)
26 
27 print(f"Time 0, ip1: {cb.is_bot(0, 'ip1')}") # False
28 print(f"Time 1, ip1: {cb.is_bot(1, 'ip1')}") # False
29 print(f"Time 1, ip1: {cb.is_bot(1, 'ip1')}") # True (3 hits at/after time -2)
30 print(f"Time 4, ip2: {cb.is_bot(4, 'ip2')}") # False
31 print(f"Time 5, ip1: {cb.is_bot(5, 'ip1')}") # False (Timestamps 0 and 1 expired)