Direction Change

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

Make it Increasing

brute force, greedy, math

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

Deletive Editing

greedy

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

Array Cloning Technique

constructive algorithms, greedy, sortings

GCD vs LCM

constructive algorithms, math

Cross-Language Program

*special problem, constructive algorithms

Six Characters

*special problem, constructive algorithms, strings

In Every Generation...

*special problem, strings

Are You Safe?

*special problem, implementation

Is it rated - 3

*special problem, combinatorics, dp, math

Pōja Verdon

*special problem, implementation, math

Mike's Sequence

*special problem, divide and conquer, implementation, math

Who Tested?

*special problem, expression parsing, trees

Circular Maze

brute force, dfs and similar, graphs, implementation

Drone Photo

combinatorics, math, sortings

Bottle Arrangements

constructive algorithms

Il Derby della Madonnina

data structures, dp, math

Pandemic Restrictions

geometry, ternary search

Training Camp

flows, graphs

Ice Cream Shop

brute force, implementation, sortings

Boundary

brute force, math

Gastronomic Event

dp, greedy, trees

Antennas

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

Round Table

math

Evolution of Weasels

greedy, implementation, strings

European Trip

dp, graphs, math, matrices

Toys

greedy, strings

Organizing SWERC

brute force, implementation

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

Getting Zero

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

Array Balancing

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

Get an Even String

dp, greedy, strings

Vlad and Candies

math

Vasya and Coins

greedy, math

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

Line Empire

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

Bit Flipping

bitmasks, constructive algorithms, greedy, strings

Red Versus Blue

constructive algorithms, greedy, implementation, math

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

Marin and Anti-coprime Permutation

combinatorics, math, number theory

Marin and Photoshoot

constructive algorithms, implementation, 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

Bracket Sequence Deletion

greedy, implementation

XY Sequence

greedy

Integer Moves

brute force, math

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

Make Equal With Mod

constructive algorithms, math, number theory, sortings

Subtract Operation

data structures, greedy, math, two pointers

Good Pairs

math, sortings

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

Alice and the Cake

data structures, greedy, implementation, sortings

Prefix Removals

strings

Maximum Cake Tastiness

brute force, greedy, implementation, sortings

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

Fault-tolerant Network

brute force, data structures, implementation