general: ex3: add solution

general/ex3.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python
+
+
+def solution(n: int) -> bool:
+    if n < 0:
+        n = -n
+
+    while n:
+        if n % 2 == 1:
+            return False
+        n //= 10
+
+    return True
+
+
+if __name__ == "__main__":
+    print(solution(0))
+    print(solution(1))
+    print(solution(2468))
+    print(solution(1468))
+    print(solution(-2468))
+    print(solution(-2469))