Follow Traffic Rules

implementation, math

Longest Regular Bracket Sequence

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

Center Alignment

implementation, strings

Chat Servers Outgoing Traffic

implementation

Mysterious Present

dp, sortings

Registration System

data structures, hashing, implementation

Before an Exam

constructive algorithms, greedy

Watermelon

brute force, math

Least Cost Bracket Sequence

greedy

Tic-tac-toe

brute force, games, implementation

Lorry

greedy, sortings

Shortest path of the king

greedy, shortest paths

Commentator problem

geometry

The least round way

dp, math

Winner

hashing, implementation

Ancient Berland Circus

geometry, math

Spreadsheet

implementation, math

Theatre Square

math