City Union

constructive algorithms, dfs and similar, dsu, geometry, greedy, implementation, math

Decreasing Game

constructive algorithms, dfs and similar, dp, greedy, interactive

Almost Fault-Tolerant Database

brute force, constructive algorithms, dfs and similar, greedy, implementation

Happy Tree Party

data structures, dfs and similar, graphs, math, trees

You

dfs and similar, dp, math, number theory

Interactive Game with Coloring

brute force, constructive algorithms, dfs and similar, graphs, implementation, interactive, trees

BFS Trees

combinatorics, dfs and similar, graphs, math, shortest paths, trees

Falling Sand (Easy Version)

dfs and similar, graphs, greedy

Jordan Smiley

*special problem, dfs and similar, geometry, implementation

Simple Cycles Edges

dfs and similar, graphs, trees

Move and Swap

dfs and similar, dp, greedy, trees

Break Up

dfs and similar, graphs

Drazil and Morning Exercise

dfs and similar, dp, dsu, trees, two pointers

Light Bulbs (Hard Version)

combinatorics, data structures, dfs and similar, dp, graphs, hashing

Leaf Sets

data structures, dfs and similar, dsu, graphs, greedy, sortings, trees

Tenzing and Tree

dfs and similar, greedy, shortest paths, sortings, trees

Diameter Cuts

combinatorics, dfs and similar, dp, trees

The Hidden Pair (Hard Version)

binary search, dfs and similar, graphs, interactive, shortest paths, trees

Tree Folding

dfs and similar, dp, greedy, implementation, trees

Rollbacks (Easy Version)

brute force, data structures, dfs and similar, trees

LuoTianyi and XOR-Tree

data structures, dfs and similar, dp, dsu, greedy, trees

Expected diameter of a tree

binary search, brute force, dfs and similar, dp, sortings, trees

Circular Maze

brute force, dfs and similar, graphs, implementation

Power Tree

dfs and similar, dp, dsu, graphs, greedy, trees

Three Pieces

dfs and similar, dp, shortest paths

Dima and Trap Graph

binary search, data structures, dfs and similar, dsu, shortest paths, two pointers

Tree-String Problem

*special problem, dfs and similar, hashing, strings

Koxia and Tree

combinatorics, dfs and similar, dp, dsu, math, probabilities, trees

Weak Memory

dfs and similar, dsu

Fast Travel Text Editor

data structures, dfs and similar, graphs, shortest paths

Divisors and Table

brute force, dfs and similar, dp, number theory

PermuTree (hard version)

bitmasks, dfs and similar, dp, fft, greedy, implementation, math, trees

Network Safety

dfs and similar, dsu, graphs, math, sortings

Columns Swaps

2-sat, dfs and similar, dsu, graphs, implementation

Distinctive Roots in a Tree

data structures, dfs and similar, dp, trees

Graph Cutting

dfs and similar, graphs

Solitaire

dfs and similar, dp

Okabe and City

dfs and similar, graphs, shortest paths

Routing

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

EKG

brute force, dfs and similar

The Hidden Pair (Easy Version)

binary search, dfs and similar, graphs, interactive, shortest paths, trees

Compressed Tree

dfs and similar, dp, graphs, greedy, sortings, trees

Bear and Forgotten Tree 2

dfs and similar, dsu, graphs, trees

Orientation of Edges

dfs and similar, graphs

Johnny and Megan's Necklace

binary search, bitmasks, constructive algorithms, dfs and similar, dsu, graphs

Caisa and Tree

brute force, dfs and similar, math, number theory, trees

DFS Trees

dfs and similar, dsu, graphs, greedy, sortings, trees

Knapsack

dfs and similar, dp, greedy

Purple Crayon

data structures, dfs and similar, games, graphs, greedy, math, sortings, trees

Kirill and Company

bitmasks, brute force, dfs and similar, dp, flows, graphs, shortest paths

Complete the MST

bitmasks, brute force, data structures, dfs and similar, dsu, graphs, greedy, trees

Paint it really, really dark gray

dfs and similar

Pairs of Pairs

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

Graph Coloring

dfs and similar, graphs

Divisors

brute force, dfs and similar, implementation, number theory

Plan of Lectures

constructive algorithms, dfs and similar, dsu, graphs, implementation, sortings, trees

Sereja and Periods

binary search, dfs and similar, strings

Infinite Card Game

binary search, brute force, data structures, dfs and similar, dp, dsu, games, graphs, greedy, sortings, two pointers

Spanning Tree Queries

binary search, data structures, dfs and similar, dsu, graphs, greedy, math, sortings, trees

Team-Building

data structures, dfs and similar, dsu, graphs

AND-MEX Walk

bitmasks, brute force, constructive algorithms, dfs and similar, dsu, graphs

Omsk Metro (hard version)

data structures, dfs and similar, divide and conquer, dp, math, trees

Sum Balance

bitmasks, dfs and similar, dp, graphs

Wizard's Tour

constructive algorithms, dfs and similar, graphs

Looksery Party

constructive algorithms, dfs and similar, graphs, greedy

Vlad and Avoiding X

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

Prime Gift

binary search, dfs and similar, math, meet-in-the-middle, number theory, two pointers

Road Improvement

*special problem, dfs and similar, graphs, greedy, trees

Shortest Path Problem?

dfs and similar, graphs, math

Demiurges Play Again

dfs and similar, dp, math, trees

Noise Level

dfs and similar, implementation, math

Session in BSU

binary search, dfs and similar, dsu, graph matchings, graphs

Sasha and the Happy Tree Cutting

bitmasks, brute force, dfs and similar, dp, graphs, greedy, math, trees

Black and White Tree

dfs and similar, greedy, trees

There Should Be a Lot of Maximums

brute force, data structures, dfs and similar, dp, trees, two pointers

e-Government

data structures, dfs and similar, dp, strings, trees

Vladik and Favorite Game

constructive algorithms, dfs and similar, graphs, interactive

Prefix Enlightenment

dfs and similar, dsu, graphs

Unique Occurrences

data structures, dfs and similar, divide and conquer, dp, dsu, trees

Cactus

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

Scheme

dfs and similar, graphs, trees

Intersecting Subtrees

dfs and similar, interactive, trees

Wires

dfs and similar, graphs, greedy

Treeland Tour

data structures, dfs and similar, dp, trees

Tree Destruction

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

EKG

dfs and similar, dp

Little Pony and Summer Sun Celebration

constructive algorithms, dfs and similar, graphs

Invariance of Tree

constructive algorithms, dfs and similar, greedy, trees

Graph Transpositions

dfs and similar, graphs, greedy, shortest paths

Square Root of Permutation

combinatorics, constructive algorithms, dfs and similar, graphs, math

Fair Share

constructive algorithms, data structures, dfs and similar, graph matchings, graphs

Cactus Wall

constructive algorithms, dfs and similar, graphs, shortest paths

Egor in the Republic of Dagestan

constructive algorithms, dfs and similar, dp, graphs, greedy, shortest paths

Berland and the Shortest Paths

brute force, dfs and similar, graphs, shortest paths

Ice cream coloring

constructive algorithms, dfs and similar, greedy

Fairy

dfs and similar, divide and conquer, dsu

Minimal Diameter Forest

constructive algorithms, dfs and similar, greedy, trees

Sasha and the Wedding Binary Search Tree

brute force, combinatorics, data structures, dfs and similar, math, trees

Quantifier Question

dfs and similar, dp, graphs, math

President and Roads

dfs and similar, graphs, hashing, shortest paths