feat: add timer

Signed-off-by: Tuan-Dat Tran <tuan-dat.tran@dextradata.com>

programming/tcp-back-to-school/main.py

@@ -1,6 +1,7 @@
 import math
 import re
 import socket
+import time
 
 
 HOST = "challenge01.root-me.org"
@@ -22,7 +23,9 @@ def solve_prompt(prompt: str) -> str:
 
 
 def main() -> None:
-    with socket.create_connection((HOST, PORT), timeout=2) as conn:
+    conn = socket.create_connection((HOST, PORT), timeout=2)
+    start_time = time.monotonic()
+    try:
         prompt = conn.recv(4096).decode(errors="replace")
         print(prompt, end="")
 
@@ -31,6 +34,10 @@ def main() -> None:
 
         result = conn.recv(4096).decode(errors="replace")
         print(result, end="")
+    finally:
+        conn.close()
+        elapsed = time.monotonic() - start_time
+        print(f"\nConnection lifetime: {elapsed:.3f}s")
 
 
 if __name__ == "__main__":