icpc probs

kattis/23-9-24/f/solution.py

@@ -0,0 +1,32 @@
+import sys
+from collections import Counter
+
+
+def solve() -> None:
+    counter: Counter[str] = Counter()
+
+    ans = []
+
+    lines = sys.stdin.readlines()
+    for line in lines:
+        first, last = line.split()
+
+        counter[first] += 1
+
+        ans.append((last, first))
+
+    ans.sort()
+
+    for last, first in ans:
+        if counter[first] > 1:
+            print(f"{first} {last}")
+        else:
+            print(first)
+
+
+def main() -> None:
+    solve()
+
+
+if __name__ == "__main__":
+    main()