Stock Exchange

binary search, flows, graphs

Pisces

data structures, flows, trees

Oleg and chess

data structures, divide and conquer, flows, graph matchings

Showing Off

flows, graph matchings, greedy, implementation

One Billion Shades of Grey

flows, graphs

Breadboard Capacity (easy version)

dp, flows, greedy

Rainbow Triples

binary search, data structures, flows, greedy

Starry Night Camping

constructive algorithms, flows, graphs

Special Edges

flows, graphs

Chests and Keys

bitmasks, brute force, dfs and similar, dp, flows

ALT

data structures, flows, graphs, trees

New Year and Forgotten Tree

constructive algorithms, flows, graphs

Demonic Invasion

*special problem, flows

Parametric Circulation

binary search, flows

Projectors

flows, graphs

Cow and Exercise

flows, graphs, shortest paths

Captain America

flows, greedy

Flow Optimality

constructive algorithms, flows, math

Maximum Flow

flows, graphs

Privatization

flows, graphs

Planar Graph

flows, geometry, graphs

Gosha is hunting

brute force, data structures, dp, flows, math, probabilities, sortings

Pills

brute force, flows

April Fools' Problem (hard)

binary search, data structures, flows

Chess Championship

constructive algorithms, flows, greedy, math

Shake It!

combinatorics, dp, flows, graphs

Red-Blue Graph

constructive algorithms, flows

Nanami's Power Plant

flows

Pumping Stations

brute force, dfs and similar, divide and conquer, flows, graphs, greedy, trees

Buying Sets

flows, graph matchings

Incorrect Flow

flows

Goods transportation

dp, flows, greedy

Scaygerboss

flows

Bricks

flows, graph matchings, graphs

k-Maximum Subsequence Sum

data structures, flows, graphs, implementation

The Doctor Meets Vader (Hard)

flows, shortest paths

World Evil

dp, flows

Scaygerboss

flows

Electric Scheme

flows, graph matchings

Yet Another Maxflow Problem

data structures, flows, graphs

Beautiful League

constructive algorithms, flows, graph matchings

Bits of merry old England

flows, graphs

Zoning Restrictions

dp, flows, graphs

Strange Set

flows, math

Heidi and Library (hard)

flows

Four Melodies

flows, graphs

Politics

flows, graphs

Yet Another DAG Problem

bitmasks, dfs and similar, dp, flows, graphs, math

Button Lock

flows, graph matchings, graphs

Vasya and Endless Credits

dp, flows, graph matchings, graphs, sortings

Two Melodies

dp, flows

Last chance

data structures, flows, graph matchings, graphs, trees

Gang Up

flows, graphs

Minimal k-covering

flows, graphs

Bear and Fair Set

flows

Anti-Palindromize

flows, graphs, greedy

Rectangle Painting 2

flows, graph matchings, graphs

Summoning Minions

constructive algorithms, dp, flows, graph matchings, greedy, sortings

Cactusophobia

dfs and similar, flows

April Fools' Problem (medium)

binary search, flows, graphs

Privatization of Roads in Berland

flows, graph matchings, graphs

Students Initiation

binary search, flows, graphs

Underfail

flows

Allowed Letters

bitmasks, flows, graph matchings, graphs, greedy

Card Game

binary search, flows, graphs

Economic Difficulties

data structures, dfs and similar, dp, flows, graphs, trees

Machine Programming

flows, graphs

Binary Tree on Plane

flows, trees

Maximize Mex

flows, graph matchings, graphs

Petya and Graph

flows, graphs

Four Points

brute force, constructive algorithms, flows, geometry, greedy, implementation, math, ternary search

Deciphering

flows, graph matchings

Horseback Riding

flows, graphs

Evacuation

flows, graphs, shortest paths

Road Construction

flows, graphs

Tidying Up

flows, graph matchings

Biologist

flows

Petya and Pipes

flows, graphs, shortest paths

Ann and Books

data structures, flows, hashing

Fox And Dinner

flows

The Doctor Meets Vader (Medium)

flows, graph matchings, graphs, shortest paths, sortings

Tidying Up

flows

Almost Permutation

flows

One-Way Reform

constructive algorithms, dfs and similar, flows, graphs, greedy

Delivery Bears

binary search, flows, graphs

Little C Loves 3 II

brute force, constructive algorithms, flows, graph matchings

Paired Payment

binary search, brute force, constructive algorithms, dp, flows, graphs, shortest paths

Exploration plan

binary search, flows, graph matchings, shortest paths

Flawed Flow

constructive algorithms, flows, graphs, greedy

Array and Operations

flows, graph matchings, number theory

Soldier and Traveling

flows, graphs, math

Olympiad in Programming and Sports

dp, flows, graphs, greedy

Build String

flows, graphs

Segments Removal

data structures, dsu, flows, implementation, two pointers

Engineer Artem

2-sat, chinese remainder theorem, constructive algorithms, fft, flows

Valuable Paper

binary search, flows, graph matchings, graphs

Ciel and Duel

dp, flows, greedy

Single-use Stones

binary search, flows, greedy, two pointers

Treasure Island

dfs and similar, dp, flows, hashing

T-shirts Distribution

constructive algorithms, flows, greedy