Fenwick Tree

brute force, combinatorics, data structures, dp, math, matrices, trees

Frequency Mismatch (Hard Version)

binary search, data structures, dfs and similar, hashing, probabilities, trees

Frequency Mismatch (Easy Version)

binary search, data structures, divide and conquer, hashing, probabilities, trees

Thanos Snap

binary search, dp, games, greedy, trees

0, 1, 2, Tree!

bitmasks, brute force, greedy, implementation, trees

Amanda the Amoeba

graphs, implementation, trees, two pointers

Dating

greedy, sortings, trees

Annual Ants' Gathering

dfs and similar, dp, greedy, trees

MST with Matching

bitmasks, brute force, dsu, graph matchings, trees

Tree Cutting

binary search, dp, greedy, implementation, trees

Tree Compass

constructive algorithms, dfs and similar, greedy, trees

Farmer John's Favorite Intern

data structures, dp, flows, trees

Burenka and Pether

*special problem, data structures, dfs and similar, divide and conquer, dsu, graphs, sortings, trees

Evidence Board

*special problem, constructive algorithms, dfs and similar, graphs, trees

Andrey's Tree

binary search, constructive algorithms, data structures, dfs and similar, dsu, greedy, implementation, trees

Interactive Mex Tree

constructive algorithms, dfs and similar, interactive, trees

Prefix Max Set Counting

data structures, dp, trees

Sasha and the Wedding Binary Search Tree

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

Sasha and the Happy Tree Cutting

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

Sasha and a Walk in the City

combinatorics, dp, math, trees

Microcycle

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

Vlad and Trouble at MIT

dfs and similar, dp, flows, graphs, greedy, implementation, trees

Count Paths

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

Smooth Sailing (Hard Version)

binary search, data structures, dsu, geometry, graphs, trees

Tree Diameter

interactive, trees

Tree LGM

constructive algorithms, divide and conquer, games, trees

01 Tree

constructive algorithms, data structures, dsu, greedy, sortings, trees

Caterpillar on a Tree

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

Construct Tree

bitmasks, constructive algorithms, dp, trees

Optimizations From Chelsu

divide and conquer, dp, number theory, trees

Happy Life in University

data structures, dfs and similar, greedy, trees

Light Bulbs (Easy Version)

brute force, combinatorics, dfs and similar, dp, dsu, graphs, math, trees

Programming Competition

dfs and similar, dp, graph matchings, greedy, trees

Array Collapse

data structures, divide and conquer, dp, trees

Build Railway Stations

*special problem, greedy, trees

One-X

combinatorics, dfs and similar, dp, math, trees

Begginer's Zelda

greedy, trees

Beautiful Tree

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

Tree Queries

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

Babysitting

2-sat, binary search, data structures, graphs, trees

Trees and XOR Queries Again

data structures, dfs and similar, divide and conquer, graphs, implementation, math, trees

Collapsing Strings

data structures, strings, trees

Compressed Tree

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

Anji's Binary Tree

dfs and similar, dp, trees

Unusual Entertainment

data structures, dfs and similar, dsu, shortest paths, sortings, trees, two pointers

Alex's whims

constructive algorithms, graphs, greedy, shortest paths, trees

XOR Construction

bitmasks, constructive algorithms, data structures, math, string suffix structures, trees

A Growing Tree

data structures, dfs and similar, trees

Doremy's Average Tree

data structures, dp, greedy, trees

Doremy's Swapping Trees

dfs and similar, graphs, trees

Game of Stacks

brute force, dfs and similar, graphs, implementation, trees

Split

binary search, data structures, divide and conquer, dsu, math, trees, two pointers

Tree XOR

bitmasks, dfs and similar, dp, greedy, trees

Minimum Maximum Distance

dfs and similar, dp, graphs, shortest paths, trees

Interactive Game with Coloring

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

wxhtzdy ORO Tree

binary search, bitmasks, brute force, data structures, dfs and similar, implementation, trees

Clubstep

binary search, brute force, data structures, greedy, trees

Ball-Stackable

constructive algorithms, data structures, dp, trees

Mad City

dfs and similar, dsu, games, graphs, shortest paths, trees

Standard Graph Problem

data structures, graphs, greedy, trees

Flower-like Pseudotree

constructive algorithms, graphs, greedy, implementation, trees

Travel Plan

combinatorics, dp, implementation, math, trees

Keen Tree Calculation

binary search, data structures, dp, geometry, graphs, implementation, trees

Guess Game

bitmasks, data structures, games, math, probabilities, sortings, strings, trees

Redundant Routes

constructive algorithms, dp, trees

Goldberg Machine 3

dp, trees

Queries for the Array

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

Teleportation in Byteland

data structures, dfs and similar, divide and conquer, graphs, shortest paths, trees

Rollbacks (Hard Version)

data structures, interactive, trees

Rollbacks (Easy Version)

brute force, data structures, dfs and similar, trees

Counting Graphs

combinatorics, divide and conquer, dsu, graphs, greedy, sortings, trees

Strong Vertices

math, sortings, trees

PermuTree (hard version)

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

PermuTree (easy version)

dfs and similar, dp, trees

Michael and Hotel

binary search, interactive, trees

Vlad and the Mountains

binary search, data structures, dsu, graphs, implementation, sortings, trees, two pointers

Lisa and the Martians

bitmasks, greedy, math, strings, trees

XOR Partition

binary search, bitmasks, data structures, divide and conquer, greedy, trees

Tree Weights

bitmasks, constructive algorithms, data structures, dfs and similar, implementation, math, matrices, number theory, trees

Omsk Metro (hard version)

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

Omsk Metro (simple version)

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

Apple Tree

combinatorics, dfs and similar, dp, math, trees

Sum in Binary Tree

bitmasks, combinatorics, math, trees

Tenzing and Tree

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

Playoff Fixing

combinatorics, trees

Ksyusha and Chinchilla

constructive algorithms, dfs and similar, dp, dsu, greedy, implementation, trees

Mex Tree

brute force, dp, trees

Copil Copac Draws Trees

dfs and similar, dp, graphs, trees

Bus Routes

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

Two Centroids

data structures, dfs and similar, greedy, trees

Range Sorting (Easy Version)

binary search, dp, dsu, greedy, trees, two pointers

LuoTianyi and Cartridge

data structures, trees

LuoTianyi and XOR-Tree

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

LuoTianyi and the Floating Islands (Hard Version)

combinatorics, dfs and similar, math, probabilities, trees

LuoTianyi and the Floating Islands (Easy Version)

combinatorics, math, probabilities, trees

Random Walk

dp, graphs, math, probabilities, trees

Gardening Friends

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

Roads in E City

interactive, math, probabilities, trees

The Fox and the Complete Tree Traversal

constructive algorithms, dp, implementation, math, trees

Sum Graph

brute force, constructive algorithms, graphs, implementation, interactive, shortest paths, trees