Codeforces Round #730 (Div. 2) D1. RPD and Rap Sheet (Easy Version)
D - 射撃王
C - 収集王
C - 双子と○×ゲーム
C - ウサギ跳び
C - おやつ
Educational Codeforces Round 111 (Rated for Div. 2) C. Manhattan Subarrays
Codeforces Round #734 (Div. 3) D1. Domino (easy version)
Codeforces Round #735 (Div. 2) B. Cobb
Codeforces Round #737 (Div. 2) C. Moamen and XOR