October Challenge 2020 Division 2
Positive AND, Random Knapsack, Rooted Minimum Spanning Tree, Replace for X, D-Dimensional MST, Compress all Subsegments, Adding Squares, Village Road Network, Covid Run, Chef and Easy Queries, Inversions
November Challenge 2020 Division 2
Ada and Dishes, Iron, Magnet and Wall, Unusual Queries, Scalar Product Tree, Red-Black Boolean Expression, Selecting Edges, Magical Candy Store, Restore Sequence, Chef and the Combination Lock
January Challenge 2021 Division 2
Guess the Tiling, And-Or Game, Sequence Creation, Fair Elections, Watching CPL, Stack-Queue Sort (Challenge), Expected Number of SCCs, Chef and Ants, Curious Matrix, Cool Subsets, Blackjack
February Challenge 2021 Division 1
Dream and the Multiverse, Cell Shell, Bash Matrix, XOR Sums, Multiple Games, Prime Game, Another Tree with Number Theory, Team Name
April Challenge 2021 Division 1
Binary String MEX, Tree Permutations, Worthy Matrix, Destroy the EMP Chip, String Power, Chef and Dice, Boolean Game
China