Letters and Question Marks

bitmasks, dp, string suffix structures

AND Segments

bitmasks, combinatorics, data structures, dp, two pointers

Count The Blocks

combinatorics, dp, math

Infinite Path

brute force, dfs and similar, graphs, math, number theory

Game with Chips

constructive algorithms, implementation

Spiderweb Trees

dp, geometry, trees

Wise Men (Hard Version)

bitmasks, dp, math

Wise Men (Easy Version)

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

Bombs

data structures, two pointers

Prefix-Suffix Palindrome (Hard version)

binary search, greedy, hashing, string suffix structures, strings

Prefix-Suffix Palindrome (Easy version)

hashing, string suffix structures, strings

Ehab's Last Theorem

constructive algorithms, dfs and similar, graphs, greedy

Ehab's REAL Number Theory Problem

brute force, dfs and similar, graphs, number theory, shortest paths

Ehab the Xorcist

bitmasks, constructive algorithms, greedy, number theory

Ehab and Path-etic MEXs

constructive algorithms, dfs and similar, greedy, trees

Maximum White Subtree

dfs and similar, dp, graphs, trees

Sleeping Schedule

dp, implementation

Pair of Topics

binary search, data structures, sortings, two pointers

Count Subrectangles

binary search, greedy, implementation

Assigning Fares

dp, trees

Median Mountain Range

data structures

Reality Show

bitmasks, dp

Instant Noodles

graphs, hashing, math, number theory

Present

binary search, bitmasks, constructive algorithms, data structures, math, sortings

Remove Adjacent

brute force, constructive algorithms, greedy, strings

Blocks and Sensors

brute force

Treeland and Viruses

data structures, dfs and similar, dp, shortest paths, trees

Reachable Strings

data structures, hashing, strings

World of Darkraft: Battle for Azathoth

brute force, data structures, sortings

Navigation System

dfs and similar, graphs, shortest paths

Journey Planning

data structures, dp, greedy, math, sortings

Battalion Strength

data structures, divide and conquer, probabilities

Team Building

bitmasks, dp, greedy, sortings

Nash Matrix

constructive algorithms, dfs and similar, graphs, implementation

Primitive Primes

constructive algorithms, math, ternary search

String Modification

brute force, constructive algorithms, implementation, sortings, strings

Concatenation with intersection

data structures, hashing, strings, two pointers

Happy New Year

bitmasks, dp, implementation

Skyscrapers (hard version)

data structures, dp, greedy

Skyscrapers (easy version)

brute force, data structures, dp, greedy

Different Rules

constructive algorithms, greedy, implementation, math

Autocompletion

data structures, dfs and similar, dp

Attack on Red Kingdom

games, two pointers

Array Shrinking

dp, greedy

Count the Arrays

combinatorics, math

Adding Powers

bitmasks, greedy, implementation, math, number theory, ternary search

Moving Points

data structures, divide and conquer, implementation, sortings

Construct the Binary Tree

brute force, constructive algorithms, trees

Three Integers

brute force, math

Bad Cryptography

math, number theory

Strange Function

dp

Tourism

dp, graphs, probabilities

Au Pont Rouge

binary search, dp, strings

Double Elimination

dp, implementation

Recommendations

data structures, greedy, sortings

Cow and Exercise

flows, graphs, shortest paths

Cow and Vacation

dfs and similar, dsu, trees

Cow and Treats

binary search, combinatorics, dp, greedy, implementation, math

Cow and Fields

binary search, data structures, dfs and similar, graphs, greedy, shortest paths, sortings

Cow and Message

brute force, dp, math, strings

Kuroni the Private Tutor

binary search, greedy

Kuroni and Antihype

bitmasks, brute force, dp, dsu, graphs

Kuroni and the Punishment

math, number theory, probabilities

Kuroni and the Score Distribution

constructive algorithms, greedy, implementation, math

Kuroni and the Celebration

constructive algorithms, dfs and similar, interactive, trees

Kuroni and Impossible Calculation

brute force, combinatorics, math, number theory

Animal Observation (hard version)

data structures, dp, greedy

Animal Observation (easy version)

data structures, dp

1-Trees and Queries

data structures, dfs and similar, shortest paths, trees

Shortest and Longest LIS

constructive algorithms, graphs, greedy, two pointers

Air Conditioner

dp, greedy, implementation, sortings, two pointers

Sum of Prefix Sums

data structures, divide and conquer, geometry, trees

Number of Components

dsu, implementation

Erase Subsequences

dp, strings

Fill The Bag

bitmasks, greedy

Perfect Keyboard

dfs and similar, greedy, implementation

National Project

math

Super Jaber

dfs and similar, graphs, implementation, shortest paths

Nanosoft

binary search, data structures, dp, implementation

Time to Run

constructive algorithms, graphs, implementation

Ayoub's function

binary search, combinatorics, greedy, math, strings

Motarack's Birthday

binary search, greedy, ternary search

So Mean

interactive, math

Around the World

bitmasks, combinatorics, dfs and similar, dp, graphs, graphs, math, trees

Water Balance

data structures, geometry, greedy

Aerodynamic

geometry

Anu Has a Function

brute force, greedy, math

Berland Beauty

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

String Coloring (hard version)

data structures, dp

String Coloring (easy version)

constructive algorithms, dp, graphs, greedy, sortings

Fight with Monsters

greedy, sortings

Yet Another Walking Robot

data structures, implementation

Good Contest

combinatorics, dp, probabilities

Permutation Separation

data structures, divide and conquer

Same GCDs

math, number theory

Obtain The String

dp, greedy, strings

Infinite Prefixes

math, strings

Three Paths on a Tree

dfs and similar, dp, greedy, trees

Obtain a Permutation

greedy, implementation, math

MEX maximizing

data structures, greedy, implementation, math