Cinema Cashier

dp, implementation

Interestring graph and Apples

dfs and similar, dsu, graphs

How many trees?

combinatorics, divide and conquer, dp

Beads

dp, graphs

Two Friends

binary search, geometry

Looking for Order

bitmasks, dp

Obsession with Robots

constructive algorithms, graphs, implementation

Defining Macros

dp, expression parsing, implementation

Palindrome Degree

hashing, strings

Line

math, number theory

Memory Manager

implementation

Exposition

binary search, data structures, dsu, trees, two pointers

Lizards and Basements 2

brute force, dp

Bindian Signalizing

data structures

Follow Traffic Rules

implementation, math

Longest Regular Bracket Sequence

constructive algorithms, data structures, dp, greedy, sortings, strings

Mysterious Present

dp, sortings

Least Cost Bracket Sequence

greedy

Tic-tac-toe

brute force, games, implementation

Lorry

greedy, sortings

Commentator problem

geometry

The least round way

dp, math

Winner

hashing, implementation

Ancient Berland Circus

geometry, math

Spreadsheet

implementation, math