Edge Queries

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

Node Pairs

dp, graphs, math, number theory

Valid Bitonic Permutations

combinatorics, dp, implementation, math, number theory

Good Pairs

binary search, data structures, dp

Anti-median (Hard Version)

combinatorics, dp, math

Anti-median (Easy Version)

dp, math

The Humanoid

brute force, dp, sortings

Wish I Knew How to Sort

dp, math, probabilities

Make Nonzero Sum (hard version)

constructive algorithms, dp, greedy

Make Nonzero Sum (easy version)

constructive algorithms, dp, greedy

BinaryStringForces

constructive algorithms, data structures, dp

Doping

combinatorics, dp, math

Majority

combinatorics, dp, math, strings

Bracket Cost

binary search, data structures, divide and conquer, dp, greedy, strings

Counting Arrays

combinatorics, dp, math, number theory

Yet Another Array Counting Problem

binary search, data structures, divide and conquer, dp, flows, math, trees

Zero-Sum Prefixes

brute force, data structures, dp, greedy, implementation

List Generation

combinatorics, dp, math

Olympiad Training

binary search, data structures, dp, flows, geometry, implementation, sortings

Joking (Hard Version)

dp, interactive

Paths on the Tree

dfs and similar, dp, greedy, sortings, trees

Antifibonacci Cut

bitmasks, combinatorics, constructive algorithms, data structures, dp, hashing, math

Intersection and Union

data structures, dp, matrices, probabilities

FTL

binary search, dp

Problem with Random Tests

brute force, dp, greedy, probabilities

Save the Magazines

constructive algorithms, dp, greedy

Kirill and Company

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

Sending a Sequence Over the Network

dp

Arranging Crystal Balls

data structures, divide and conquer, divide and conquer, dp, geometry, graphs, number theory

Conditional Mix

combinatorics, dp, math

Hanging Hearts

constructive algorithms, data structures, dfs and similar, dp, greedy, trees

Keyboard Design

bitmasks, data structures, dp, string suffix structures, strings

Cleaning Robot

bitmasks, dp

Card Game

combinatorics, constructive algorithms, dp, games

Anti-Increasing Addicts

constructive algorithms, dp, greedy, math

Balance Addicts

combinatorics, dp, math, two pointers

Even Number Addicts

dp, games, greedy, math

Ela Goes Hiking

combinatorics, dp, math, probabilities

Ela and the Wiring Wizard

brute force, dp, graphs, greedy, implementation, shortest paths

Swap and Take

dp, greedy

Good Subarrays (Hard Version)

binary search, data structures, dp, two pointers

Zeros and Ones

bitmasks, divide and conquer, dp, math

Slime Escape

data structures, dp, greedy, two pointers

Conveyor

constructive algorithms, dp, math

Zero-One (Hard Version)

dp, greedy

Location

data structures, dp, math, number theory

Ugu

brute force, dp, greedy, implementation

Function Sum

brute force, combinatorics, dp, fft, math

Graph Cost

dp, greedy, math, number theory

Valiant's New Map

binary search, brute force, data structures, dp, two pointers

Almost Sorted

bitmasks, data structures, dp

Cut Substrings

combinatorics, dp, hashing, strings, two pointers

Illumination

binary search, bitmasks, brute force, combinatorics, dp, math, two pointers

Letter Picking

constructive algorithms, dp, games, two pointers

Moving Both Hands

dp, graphs, shortest paths

Journey

dp, trees

Electrical Efficiency

combinatorics, data structures, dp, math, number theory, trees

Counting Rectangles

brute force, data structures, dp, implementation

Prefix Function Queries

dfs and similar, dp, hashing, string suffix structures, strings, trees

Xor-Subsequence (hard version)

bitmasks, data structures, dp, strings, trees

Xor-Subsequence (easy version)

bitmasks, brute force, dp, strings, trees, two pointers

Burenka and Traditions (hard version)

data structures, dp, greedy

Burenka and Traditions (easy version)

dp, greedy

Bags with Balls

combinatorics, dp, math, number theory

Swap and Maximum Block

bitmasks, data structures, dfs and similar, divide and conquer, dp

Chip Move

brute force, dp, math

Robot in a Hallway

data structures, dp, greedy, implementation, ternary search

Long Way Home

data structures, divide and conquer, dp, geometry, graphs, greedy, shortest paths

Color with Occurrences

brute force, data structures, dp, greedy, strings

Lost Array

bitmasks, combinatorics, constructive algorithms, dp, math

Build Permutation

constructive algorithms, dp, math

XOR Triangle

bitmasks, brute force, constructive algorithms, dp, greedy, math

Multiset of Strings

bitmasks, brute force, dp, fft, flows, graphs, math, meet-in-the-middle, trees

Also Try Minecraft

data structures, dp, implementation

Bugaboo

bitmasks, constructive algorithms, dp, number theory

Partial Virtual Trees

combinatorics, dfs and similar, dp, math, trees

Chopping Carrots (Hard Version)

brute force, constructive algorithms, data structures, dp, greedy, math, number theory, two pointers

Qpwoeirut And The City

dp, flows, greedy, implementation

Making Towers

dp, greedy, math

Game of AI (easy version)

combinatorics, constructive algorithms, dp, fft, math

Colouring Game

constructive algorithms, dp, games

Count Seconds

brute force, constructive algorithms, dp, graphs, implementation, math

Good Key, Bad Key

bitmasks, brute force, dp, greedy, math

Yet Another Problem About Pairs Satisfying an Inequality

binary search, data structures, dp, greedy, sortings

Text Editor

brute force, dp, greedy, strings

Puzzle

constructive algorithms, dp, greedy

River Locks

binary search, dp, greedy, math

Three Days Grace

data structures, dp, greedy, math, number theory, two pointers

Almost Triple Deletions

data structures, dp, greedy

Coloring

brute force, combinatorics, constructive algorithms, dp, geometry, graphs, greedy, implementation, math

Maximum Product?

brute force, combinatorics, dp, greedy, implementation, math, two pointers

Tree Queries (Hard Version)

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

Tree Queries (Easy Version)

brute force, constructive algorithms, dfs and similar, dp, greedy, trees

Zero Path

brute force, data structures, dp, graphs, greedy, shortest paths

Decinc Dividing

brute force, data structures, divide and conquer, dp, greedy

Fake Plastic Trees

dfs and similar, dp, greedy, trees

Gambling

data structures, dp, greedy, math

2^Sort

data structures, dp, sortings, two pointers

K-Set Tree

combinatorics, dfs and similar, dp, math, trees

Lena and Matrix

data structures, dp, geometry, shortest paths