Unique Array

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

Carousel of Combinations

brute force, combinatorics, dp, math, number theory

The Most Reckless Defense

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

Nobody is needed

2-sat, data structures, dfs and similar, dp

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

Replace on Segment

dp, graph matchings

Mischievous Shooter

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

Counting Binary Strings

combinatorics, dp, math

Construct Tree

bitmasks, constructive algorithms, dp, trees

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 (Hard Version)

combinatorics, dp, math

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

Maximum And Queries (hard version)

bitmasks, divide and conquer, dp, greedy

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

Keen Tree Calculation

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

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

Maximum Monogonosity

brute force, dp, math

Trees and Segments

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

Expected Destruction

combinatorics, dp, math, probabilities

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

Boxes and Balls

dp, implementation, 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

Count Supersequences

combinatorics, dp, math

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

LuoTianyi and XOR-Tree

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

Removing Graph

brute force, dp, games, graphs, math

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 (medium version)

combinatorics, divide and conquer, dp, matrices

Minibuses on Venus (easy version)

combinatorics, divide and conquer, dp

DSU Master

combinatorics, dp, dsu, math

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

Gifts from Grandfather Ahmed

dp, math, number theory

Multitest Generator

brute force, dp

Colored Subgraphs

dfs and similar, dp, games, greedy, trees

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

Serval and Music Game

brute force, dp, implementation, math, 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

Xorcerer's Stones

bitmasks, constructive algorithms, dp, trees

Flexible String Revisit

combinatorics, dp, math, probabilities

Vittorio Plays with LEGO Bricks

dp, geometry

Laboratory on Pluto

constructive algorithms, dp, greedy, math

Hossam and a Letter

brute force, dp, implementation, two pointers

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

Algebra Flash

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