Codeforces Beta Round #87 (Div. 1 Only) B. Lawnmower
Codeforces Beta Round #91 (Div. 1 Only) B. Lucky Transformation
Codeforces Round #828 (Div. 3) E2. Divisible Numbers (hard version)
Codeforces Round #828 (Div. 3) E1. Divisible Numbers (easy version)
Length of Longest Subsequence
Largest Distance between nodes of a Tree
N digit numbers with digit sum S
Sub Matrices with sum Zero
Sum of pairwise Hamming Distance
B - K Cakes