Secret Message

constructive algorithms, dfs and similar, math

Formation

binary search, data structures, dp, sortings, two pointers

Another Exercise on Graphs (hard version)

binary search, dfs and similar, dp, dsu, graphs, shortest paths, sortings

Another Exercise on Graphs (Easy Version)

binary search, brute force, dp, dsu, graphs, shortest paths, sortings

Gifts Order

data structures, greedy, implementation, math, matrices

Trip to the Olympiad

bitmasks, constructive algorithms, greedy, math

Gorilla and the Exam

greedy, sortings

MEX Table

constructive algorithms, math

Xor of Median (Hard Version)

bitmasks, brute force, combinatorics, dp, math

Xor of Median (Easy Version)

bitmasks, brute force, combinatorics, dp, math

Nested Segments

combinatorics, dfs and similar, dp, dsu, math

Unique Median

binary search, brute force, combinatorics, data structures, divide and conquer, dp

Palindromic Subsequences

brute force, constructive algorithms, math

Find the Permutation

brute force, dfs and similar, graphs, implementation, sortings

Shape Perimeter

constructive algorithms, math

Cosmic Divide

brute force, geometry, hashing, math, strings

Haystacks

brute force, constructive algorithms, data structures, greedy, sortings

Scarecrow

greedy, implementation, math

The Trail

brute force, constructive algorithms, greedy, math, two pointers

Crafting

constructive algorithms, greedy, sortings

Two Frogs

constructive algorithms, games, greedy, math

Affectionate Arrays (Hard Version)

data structures, dp, graphs, greedy, math, shortest paths, two pointers

Affectionate Arrays (Easy Version)

data structures, dp, greedy

Delicate Anti-monotonous Operations

constructive algorithms, implementation

Naive String Splits

binary search, brute force, greedy, hashing, math, number theory, strings

Earnest Matrix Complement

brute force, data structures, dp, greedy, implementation, math

Resourceful Caterpillar Sequence

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

Refined Product Optimality

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

Bewitching Stargazer

bitmasks, divide and conquer, dp, math

Outstanding Impressionist

binary search, brute force, data structures, greedy

Tender Carpenter

dp, geometry, greedy, math

Managing Cluster

dp, graphs, math, trees

Legacy Screensaver

Knowns and Unknowns

Judicious Watching

binary search, greedy, sortings

Incompetent Delivery Guy

graphs, shortest paths

Hunting Hoglins in Hogwarts

interactive

Geometric Balance

data structures, geometry, implementation

Fix Flooded Floor

constructive algorithms, dp, graphs

Expression Correction

brute force, expression parsing, strings

DAG Serialization

brute force, graphs

Cactus without Bridges

constructive algorithms, math

BitBitJump

Adrenaline Rush

constructive algorithms

Snakes

bitmasks, dp, dsu, graphs

Joker

brute force, greedy, implementation, math

Best Price

binary search, brute force, data structures, greedy, sortings

Counting Pairs

binary search, sortings, two pointers

Preparing for the Exam

constructive algorithms, implementation

Journey

binary search, math

Preparing for the Olympiad

greedy

Tree Destruction

dfs and similar, dp, trees

Maximum modulo equality

data structures, divide and conquer, math, number theory

Three Strings

dp, implementation, strings

Digital string maximization

brute force, greedy, math, strings

Uninteresting Number

brute force, dp, math

Transfusion

brute force, greedy, math

Line Breaks

implementation

MEX OR Mania

bitmasks, brute force, data structures, dsu, implementation

Broken Queries

binary search, bitmasks, brute force, constructive algorithms, implementation, interactive

Shift + Esc

brute force, dp

MEX Cycle

brute force, constructive algorithms, greedy, implementation

pspspsps

brute force, constructive algorithms, graph matchings, implementation

MEX Destruction

greedy, implementation

Kevin and Puzzle (Hard Version)

bitmasks, fft, math

Kevin and Puzzle (Easy Version)

constructive algorithms

Kevin and Strange Operation

data structures, dp

Kevin and Matrices

brute force, combinatorics, dp, math

Kevin and Math Class

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

Kevin and Bipartite Graph

constructive algorithms, graphs, greedy

Kevin and Competition Memories

binary search, brute force, data structures, greedy, sortings, two pointers

Kevin and Binary Strings

bitmasks, brute force, greedy, implementation, strings

Kevin and Permutation

constructive algorithms, greedy

Kevin and Combination Lock

brute force, greedy, implementation, math, number theory

Replace Character

brute force, combinatorics, greedy, strings

Alyona and a Square Jigsaw Puzzle

implementation, math

Yandex Cuneiform (Hard Version)

constructive algorithms, data structures, greedy, implementation

Yandex Cuneiform (Easy Version)

constructive algorithms, data structures, greedy

Cheops and a Contest (Hard Version)

greedy, implementation

Cheops and a Contest (Easy Version)

constructive algorithms, greedy

For the Emperor!

flows, graphs

Adventurers

binary search, data structures, greedy, sortings, ternary search, two pointers

Move Back at a Cost

binary search, data structures, greedy, sortings

Swap Columns and Find a Path

greedy, sortings

Mirror Maze

brute force, dfs and similar, graphs, implementation

Buggy DFS

constructive algorithms

GCDDCG

Xorderable Array

bitmasks, data structures

Microwavable Subsequence

data structures

Missing Separators

dp, sortings, string suffix structures, strings

X Aura

graphs, math, shortest paths

Grid Game 3-angle

games, math

Narrower Passageway

combinatorics, data structures

Aquatic Dragon

Saraga

greedy, strings

ICPC Square

math, number theory

Scrambled Scrabble

brute force, greedy

Hard Demon Problem

constructive algorithms, data structures, dp, implementation, math

Medium Demon Problem (hard version)

dfs and similar, dp, dsu, graphs, implementation, trees

Medium Demon Problem (easy version)

dfs and similar, graph matchings, graphs, implementation, trees