Cats
Codeforces Round 610 (Div. 2) C. Petya and Exam
Codeforces Round 611 (Div. 3) D. Christmas Trees
Codeforces Round 611 (Div. 3) E. New Year Parties
Codeforces Round 612 (Div. 1) A. Garland
Codeforces Round 612 (Div. 1) B. Numbers on Tree
String Similarity
Prim’s (MST) : Special Subtree
Making Candies
Minimum Operations