The Most Reckless Defense

bitmasks, brute force, constructive algorithms, dp, flows, graph matchings, shortest paths

Girl Permutation

combinatorics, dp, math, number theory

Counting Is Fun (Easy Version)

brute force, combinatorics, dp, math

Learning to Paint

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

Turtle Mission: Robot and the Earthquake

dfs and similar, dp, graphs, shortest paths

2..3...4.... Wonderful! Wonderful!

combinatorics, dp, math

Sum over all Substrings (Hard Version)

bitmasks, divide and conquer, dp, dsu, greedy, implementation, strings

Sasha and the Happy Tree Cutting

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

Modular Sequence

brute force, constructive algorithms, dp, graphs, greedy, math, number theory

Paint Charges

data structures, dp, greedy, math

Vlad and Avoiding X

bitmasks, brute force, dfs and similar, dp, implementation

Mischievous Shooter

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

Counting Binary Strings

combinatorics, dp, math

Yet Another Inversions Problem

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

Light Bulbs (Hard Version)

combinatorics, data structures, dfs and similar, dp, graphs, hashing

Light Bulbs (Easy Version)

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

Array Collapse

data structures, divide and conquer, dp, trees

Maximum Sum Subarrays

*special problem, dp

Small Permutation Problem (Easy Version)

brute force, combinatorics, dp, math

Count BFS Graph

combinatorics, dp

Twin Friends

combinatorics, dp

One-X

combinatorics, dfs and similar, dp, math, trees

Compressed Tree

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

Transitive Graph

dfs and similar, dp, dsu, graphs, implementation

Infinite Card Game

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

I Wanna be the Team Leader

bitmasks, constructive algorithms, dp, greedy, math, sortings, two pointers

Counting Rhyme

dp, math, number theory

Jellyfish and EVA

dp, graphs, greedy, math, probabilities

Jellyfish and Math

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

Another MEX Problem

bitmasks, brute force, dp, shortest paths

Travel Plan

combinatorics, dp, implementation, math, trees

Candy Party (Hard Version)

bitmasks, constructive algorithms, dp, greedy, implementation, math

Mighty Rock Tower

brute force, combinatorics, dp, math, probabilities

Imagination Castle

dp, games, two pointers

Grouped Carriages

binary search, data structures, dp, flows, greedy

Digital Wallet

dp, greedy

Speedrun

brute force, dfs and similar, dp, graphs, greedy, math, sortings, two pointers

Non-Intersecting Subpermutations

combinatorics, dp, implementation, math

Balanced String

dp

Trees and Segments

brute force, data structures, dp, greedy, two pointers

Earn or Unlock

bitmasks, brute force, dp

Ina of the Mountain

data structures, dp, greedy, math

Max to the Right of Min

binary search, data structures, divide and conquer, dp, dsu, two pointers

Vika and Wiki

binary search, bitmasks, combinatorics, divide and conquer, dp, math

Omsk Metro (hard version)

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

Tenzing and Triangle

data structures, dp, geometry, greedy, math

Railguns

brute force, dfs and similar, dp, graphs

Decreasing Game

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

Ball Sorting

data structures, dp, sortings

Combinatorics Problem

brute force, combinatorics, dp

Range Sorting (Hard Version)

binary search, data structures, dp, greedy

Walk the Runway

bitmasks, brute force, data structures, dp, graphs, implementation, sortings

Rearrange Brackets

brute force, dp, greedy, sortings, strings

The Fox and the Complete Tree Traversal

constructive algorithms, dp, implementation, math, trees

Chain Chips

data structures, dp, matrices

Vlad and the Nice Paths (hard version)

binary search, combinatorics, data structures, dp, math, two pointers

Vlad and the Nice Paths (easy version)

combinatorics, dp, math

Two Tanks

binary search, dp, implementation, math

Minibuses on Venus (easy version)

combinatorics, divide and conquer, dp

There Should Be a Lot of Maximums

brute force, data structures, dfs and similar, dp, trees, two pointers

Routing

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

The way home

binary search, data structures, dp, graphs, greedy, shortest paths, sortings

Hot Start Up (hard version)

data structures, dp

Multitest Generator

brute force, dp

Explosions?

binary search, data structures, dp, greedy, math

Labeling the Tree with Distances

data structures, dp, greedy, hashing, implementation, trees

Divisors and Table

brute force, dfs and similar, dp, number theory

Sum Over Zero

data structures, dfs and similar, dp

Wooden Spoon

combinatorics, dp

Three Chairs

bitmasks, brute force, combinatorics, data structures, dp, number theory, sortings

Flexible String Revisit

combinatorics, dp, math, probabilities

Vittorio Plays with LEGO Bricks

dp, geometry

Hossam and (sub-)palindromic tree

brute force, data structures, dfs and similar, dp, strings, trees

Koxia and Tree

combinatorics, dfs and similar, dp, dsu, math, probabilities, trees

Count Binary Strings

data structures, dp

Decomposition

binary search, brute force, data structures, divide and conquer, dp, two pointers

Chemistry Lab

dp, geometry, probabilities

Doremy's Number Line

dp, greedy, sortings

Node Pairs

dp, graphs, math, number theory

Valid Bitonic Permutations

combinatorics, dp, implementation, math, number theory

Bracket Cost

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

Yet Another Array Counting Problem

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

Intersection and Union

data structures, dp, matrices, probabilities

FTL

binary search, dp

Kirill and Company

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

Cleaning Robot

bitmasks, dp

Balance Addicts

combinatorics, dp, math, two pointers

Ela and the Wiring Wizard

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

Good Subarrays (Hard Version)

binary search, data structures, dp, two pointers

Cut Substrings

combinatorics, dp, hashing, strings, two pointers

Prefix Function Queries

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

Xor-Subsequence (hard version)

bitmasks, data structures, dp, strings, trees

Long Way Home

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

Chopping Carrots (Hard Version)

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

Count Seconds

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

Almost Triple Deletions

data structures, dp, greedy

Coloring

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

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

Unique Occurrences

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