MEX vs DIFF

binary search, brute force, constructive algorithms, data structures, greedy, two pointers

Traps

constructive algorithms, greedy, sortings

MCMF?

data structures, flows, graphs, greedy, sortings, two pointers

Unordered Swaps

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

Circular Spanning Tree

constructive algorithms, implementation, trees

Unique Occurrences

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

Labyrinth Adventures

data structures, dp, matrices, shortest paths

Required Length

brute force, dfs and similar, dp, hashing, shortest paths

Lenient Vertex Cover

dfs and similar, divide and conquer, dsu, graphs, trees

Moving Chips

bitmasks, dp, greedy

Dog Walking

brute force, greedy, math

Binary String

binary search, greedy, strings, two pointers

Formalism for Formalism

bitmasks, dp, math

Typical Party in Dorm

bitmasks, combinatorics, dp, strings

Toss a Coin to Your Graph...

binary search, dfs and similar, dp, graphs

Tokitsukaze and Good 01-String (hard version)

dp, greedy, implementation

Tokitsukaze and Gems

dp, math

Tokitsukaze and Beautiful Subsegments

data structures

Tokitsukaze and Permutations

dp, math

Tokitsukaze and Two Colorful Tapes

constructive algorithms, dfs and similar, graphs, greedy

Tokitsukaze and Meeting

data structures, implementation, math

Tokitsukaze and Strange Inequality

brute force, data structures, dp

Sorting Pancakes

dp

Vlad and Unfinished Business

dfs and similar, dp, greedy, trees

Remove Directed Edges

dfs and similar, dp, graphs

Desktop Rearrangement

data structures, greedy, implementation

Breaking the Wall

binary search, brute force, constructive algorithms, greedy, math

Anti-Theft Road Planning

bitmasks, constructive algorithms, divide and conquer, greedy, interactive, math

Power or XOR?

bitmasks, combinatorics, math, number theory

Lost Arithmetic Progression

combinatorics, math, number theory

PermutationForces

data structures, greedy

Zigu Zagu

constructive algorithms, data structures, greedy

Cross Xor

constructive algorithms, graphs, math, matrices

Checker for Array Shuffling

constructive algorithms, dfs and similar, graphs

Array Shuffling

constructive algorithms, graphs, greedy

notepad.exe

binary search, constructive algorithms, greedy, interactive

Cyclic Rotation

constructive algorithms, greedy, implementation, two pointers

Permutation Counting

brute force, combinatorics, dp, fft, math

Preorder

combinatorics, divide and conquer, dp, dsu, hashing, sortings, trees

Insert a Progression

brute force, constructive algorithms, greedy

Jee, You See?

bitmasks, combinatorics, dp

Hemose on the Tree

bitmasks, constructive algorithms, dfs and similar, trees

Very Suspicious

binary search, brute force, geometry, greedy, implementation, math

Yin Yang

implementation

Centroid Probabilities

combinatorics, dp, fft, math

Edge Elimination

constructive algorithms, dfs and similar, dp, trees

Half Queen Cover

constructive algorithms, math

Optimal Partition

data structures, dp

Labyrinth

dfs and similar, graphs

Kingdom Partition

flows

Job Lookup

constructive algorithms, dp, shortest paths, trees

Interactive Treasure Hunt

brute force, constructive algorithms, geometry, interactive, math

Heroes of Might

math

Global Warming

geometry, math

Fancy Stack

combinatorics, dp, implementation

Even Split

binary search, constructive algorithms, greedy, math

Connect the Points

brute force, constructive algorithms, geometry

Budget Distribution

Admissible Map

MinimizOR

bitmasks, brute force, data structures, divide and conquer, greedy, implementation, two pointers

GCD Guess

bitmasks, chinese remainder theorem, constructive algorithms, games, interactive, math, number theory

Tree Infection

binary search, greedy, sortings, trees

Teleporters

binary search, greedy

Narrow Components

brute force, data structures, dp, dsu, math, trees

Progressions Covering

data structures, greedy

Water the Trees

binary search, greedy, math

Promising String (hard version)

data structures, implementation, math, strings

Promising String (easy version)

brute force, implementation, math, strings

Matrix and Shifts

brute force, constructive algorithms, greedy, implementation

Maximum Product Strikes Back

brute force, implementation, math, two pointers

Tree and Permutation Game

dfs and similar, games, graphs, trees

AND-MEX Walk

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

Reverse Sort Sum

constructive algorithms, data structures, greedy, implementation, math, two pointers

Juju and Binary String

brute force, constructive algorithms, greedy, math

Gojou and Matrix Game

data structures, dp, games, hashing, implementation, math, number theory, sortings

388535 (Hard Version)

bitmasks, brute force, data structures, math

388535 (Easy Version)

bitmasks, math

Shinju and the Lost Permutation

constructive algorithms, math

Words on Tree

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

Star MST

combinatorics, dp, graph matchings, math

For Gamers. By Gamers.

binary search, brute force, greedy, math, sortings

Neighbour Ordering

constructive algorithms, graphs

Equal LCM Subsets

data structures, math, number theory

Cycle Palindrome

constructive algorithms, graphs, math

Parametric MST

binary search, constructive algorithms, graphs, greedy, math, sortings

Equal Tree Sums

constructive algorithms, dfs and similar, math, trees

K-good

constructive algorithms, math, number theory

Three Minimums

combinatorics, constructive algorithms, divide and conquer, dp, fft, math

Snowy Mountain

data structures, dfs and similar, graphs, greedy, shortest paths, trees

Minimal String Xoration

bitmasks, data structures, divide and conquer, greedy, hashing, sortings, strings

Arithmetic Operations

brute force, data structures, graphs, math

Potion Brewing Class

dfs and similar, math, number theory, trees

Tower Defense

binary search, brute force, data structures

Sum of Matchings

brute force, combinatorics, constructive algorithms, dfs and similar, graph matchings, greedy, math

Nearest Excluded Points

binary search, data structures, dfs and similar, graphs, shortest paths

Counting Shortcuts

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

Vitaly and Advanced Useless Algorithms

dp, greedy, implementation

Rescheduling the Exam

binary search, data structures, greedy, implementation, math, sortings

Two Avenues

data structures, dfs and similar, graphs

Air Reform

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