Maximums

implementation, math

Bad Ugly Numbers

constructive algorithms, number theory

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

CopyCopyCopyCopyCopy

greedy, implementation

EhAb AnD gCd

constructive algorithms, greedy, number theory

Maximum White Subtree

dfs and similar, dp, graphs, trees

Sleeping Schedule

dp, implementation

Pair of Topics

binary search, data structures, sortings, two pointers

Frog Jumps

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

Yet Another Palindrome Problem

brute force, strings

Yet Another Tetris Problem

implementation, number theory

Count Subrectangles

binary search, greedy, implementation

Even Subset Sum Problem

brute force, dp, 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

Unusual Competitions

greedy

Remove Adjacent

brute force, constructive algorithms, greedy, strings

Contest for Robots

greedy

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

Grade Allocation

implementation

Restoring Permutation

greedy

Homecoming

binary search, dp, greedy, strings

Dead Pixel

implementation

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

Fast Food Restaurant

brute force, greedy, implementation

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

Bogosort

constructive algorithms, sortings

Two Regular Polygons

geometry, greedy, math, number theory

Moving Points

data structures, divide and conquer, implementation, sortings

Construct the Binary Tree

brute force, constructive algorithms, trees

Three Integers

brute force, math

Perform the Combo

brute force

WeirdSort

dfs and similar, sortings

Add Odd or Subtract Even

greedy, implementation, 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

Cow and Friend

geometry, greedy, math

Cow and Haybales

greedy, implementation

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

Kuroni and Simple Strings

constructive algorithms, greedy, strings, two pointers

Kuroni and the Gifts

brute force, constructive algorithms, greedy, sortings

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

Longest Palindrome

brute force, constructive algorithms, greedy, implementation, strings

Two Rabbits

math

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

Erasing Zeroes

implementation, strings

Keep talking and nobody explodes -- hard

Deja vu

Who needs suffix structures?

Keep talking and nobody explodes -- medium

Keep talking and nobody explodes -- easy

bitmasks, brute force, expression parsing

Amazing bitset

Dijkstra