Off by One

constructive algorithms, dfs and similar, geometry, graphs, sortings, trees

Fillomino 2

constructive algorithms, dfs and similar, greedy, implementation

Phoenix and Odometers

dfs and similar, graphs, math, number theory

Phoenix and Earthquake

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

Cactus Not Enough

dfs and similar, graph matchings, graphs

Tree Calendar

brute force, constructive algorithms, data structures, dfs and similar, sortings, trees

Complete the MST

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

Diameter Cuts

combinatorics, dfs and similar, dp, trees

Christmas Game

bitmasks, data structures, dfs and similar, dp, games, math, trees

Bananas in a Microwave

dfs and similar, dp, graphs, implementation

BFS Trees

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

Delete The Edges

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

Dogeforces

constructive algorithms, data structures, dfs and similar, divide and conquer, dsu, greedy, sortings, trees

Almost Fault-Tolerant Database

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

Fib-tree

brute force, dfs and similar, divide and conquer, number theory, trees

Permutation Transformation

dfs and similar, divide and conquer, implementation

Minimum Ties

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

Pairs of Paths

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

Move and Swap

dfs and similar, dp, greedy, trees

Nezzar and Hidden Permutations

constructive algorithms, dfs and similar, graphs

Pattern Matching

bitmasks, data structures, dfs and similar, graphs, hashing, sortings, strings

Journey

dfs and similar, dp, dsu, implementation

Moving to the Capital

dfs and similar, dp, graphs, shortest paths

Strange Housing

constructive algorithms, dfs and similar, graph matchings, graphs, greedy

Distinctive Roots in a Tree

data structures, dfs and similar, dp, trees

Euclid's nightmare

bitmasks, dfs and similar, dsu, graphs, greedy, math, sortings

Plan of Lectures

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

Number of Simple Paths

combinatorics, dfs and similar, graphs, trees

Dog Snacks

binary search, dfs and similar, dp, greedy, trees

Game On Tree

data structures, dfs and similar, greedy, trees

Capitalism

constructive algorithms, dfs and similar, graphs, shortest paths

Long Recovery

constructive algorithms, dfs and similar

Finding the Vertex

brute force, dfs and similar, dp, interactive, trees

Team-Building

data structures, dfs and similar, dsu, graphs

Black, White and Grey Tree

binary search, constructive algorithms, dfs and similar, dp, greedy, trees

Graph Transpositions

dfs and similar, graphs, greedy, shortest paths

Bandit in a City

binary search, dfs and similar, graphs, greedy, trees

Districts Connection

constructive algorithms, dfs and similar

Yet Another DAG Problem

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

Rain of Fire

binary search, data structures, dfs and similar, dsu, graphs, implementation

Peaceful Rooks

dfs and similar, dsu, graphs

Egor in the Republic of Dagestan

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

Link Cut Centroids

constructive algorithms, dfs and similar, graphs, trees

Game of Pairs

constructive algorithms, dfs and similar, interactive, math, number theory

Tree Tag

dfs and similar, dp, games, trees

Spring cleaning

*special problem, data structures, dfs and similar, graphs, trees

Star Trek

*special problem, combinatorics, dfs and similar, dp, games, graphs, matrices, trees

Maximum Distributed Tree

dfs and similar, dp, greedy, implementation, math, number theory, sortings, trees

x-prime Substrings

brute force, dfs and similar, dp, string suffix structures, strings

Weights Division (hard version)

binary search, dfs and similar, greedy, sortings, trees, two pointers

Weights Division (easy version)

data structures, dfs and similar, greedy, trees

Distance Matching

constructive algorithms, dfs and similar, trees

Boboniu Walks on Graph

brute force, dfs and similar, graphs, hashing

Rarity and New Dress

dfs and similar, dp, implementation, shortest paths

Omkar and Pies

bitmasks, dfs and similar, dp, math, shortest paths

Pairs of Pairs

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

Directing Edges

dfs and similar, dp, graphs, trees

Captain Flint and Treasure

data structures, dfs and similar, graphs, greedy, implementation, trees

Uncle Bogdan and Country Happiness

dfs and similar, greedy, math, trees

Village (Maximum)

*special problem, dfs and similar, trees

Graph

*special problem, binary search, dfs and similar, dp, math, ternary search

Columns Swaps

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

Directing Edges

constructive algorithms, dfs and similar, graphs

The Majestic Brown Tree Snake

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

Choosing flowers

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

Tree Modification

brute force, constructive algorithms, dfs and similar, graph matchings, graphs, trees

The Hidden Pair (Hard Version)

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

The Hidden Pair (Easy Version)

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

BareLee

dfs and similar, dp, games

DeadLee

data structures, dfs and similar, greedy, implementation, sortings

Necklace Assembly

brute force, dfs and similar, dp, graphs, greedy, number theory

Solve The Maze

constructive algorithms, dfs and similar, dsu, graphs, greedy, implementation, shortest paths

Ehab's Last Corollary

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

Tree Shuffling

dfs and similar, dp, greedy, trees

James and the Chase

dfs and similar, graphs, probabilities, trees

Johnny and Megan's Necklace

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

Graph Coloring

dfs and similar, dp, graphs

Binary String Reconstruction

constructive algorithms, dfs and similar, math

Orac and Game of Life

dfs and similar, graphs, implementation, shortest paths

Phoenix and Memory

data structures, dfs and similar, graphs, greedy

Quantifier Question

dfs and similar, dp, graphs, math

Monopole Magnets

constructive algorithms, dfs and similar, dsu, graphs

Nastya and Time Machine

constructive algorithms, dfs and similar, graphs, trees

Nastya and Unexpected Guest

dfs and similar, dp, graphs, shortest paths

Nested Rubber Bands

constructive algorithms, dfs and similar, dp, math, trees

Edge Weight Assignment

bitmasks, constructive algorithms, dfs and similar, greedy, math, trees

Linova and Kingdom

dfs and similar, dp, greedy, sortings, trees

Robots on a Grid

data structures, dfs and similar, dsu, graphs, greedy, matrices

Independent Set

dfs and similar, dp, trees

K-Complete Word

dfs and similar, dsu, greedy, implementation, strings

Jordan Smiley

*special problem, dfs and similar, geometry, implementation

Tree Queries

dfs and similar, graphs, trees

Infinite Path

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

Ehab's Last Theorem

constructive algorithms, dfs and similar, graphs, greedy

Ehab's REAL Number Theory Problem

brute force, dfs and similar, graphs, number theory, shortest paths

Ehab and Path-etic MEXs

constructive algorithms, dfs and similar, greedy, trees

Maximum White Subtree

dfs and similar, dp, graphs, trees

Frog Jumps

binary search, data structures, dfs and similar, greedy, implementation

Treeland and Viruses

data structures, dfs and similar, dp, shortest paths, trees

Navigation System

dfs and similar, graphs, shortest paths