Interactive Rays

geometry, interactive

Higher Order Functions

implementation, strings

Game of Chance

math, probabilities

Framing Pictures

geometry

Easy Scheduling

implementation, math

Dragon Curve

Cactus Lady and her Cing

Building Forest Trails

data structures, dsu

Anti-Tetris

constructive algorithms, graphs, shortest paths

Communication Routing Challenge

*special problem

Managing Telephone Poles

data structures, geometry

Longest Array Deconstruction

data structures, divide and conquer, dp, sortings

Knitting Batik

implementation, math

Jeopardy of Dropped Balls

binary search, brute force, dsu, implementation

Illusions of the Desert

data structures, trees

Holiday Wall Ornaments

dp, strings

GCD Festival

math, number theory

Finding Expected Value

math

Eye-Pleasing City Park Tour

data structures, trees

Divisible by Twenty-Five

brute force, dfs and similar, dp

Cyclic Sum

data structures, fft, number theory

Building an Amusement Park

binary search, geometry

Another Sorting Problem

data structures, sortings, strings

Occurrences

combinatorics, dfs and similar, dp, dsu, fft, graphs

Coloring

combinatorics, constructive algorithms, implementation, math

The Strongest Build

binary search, brute force, data structures, dfs and similar, graphs, greedy, hashing, implementation

Slay the Dragon

binary search, greedy, sortings, ternary search

Combinatorics Homework

combinatorics, greedy, math

Regular Bracket Sequences

constructive algorithms

Swaps

greedy, math, sortings

Countdown

greedy

Stations

data structures

Polygon

binary search, dp, geometry

Bridge Club

flows, graph matchings, graphs, greedy

Paint

dp, greedy

Xor of 3

brute force, constructive algorithms, greedy, two pointers

Book

binary search, brute force, data structures, dp, graphs, implementation, sortings

Two Railroads

*special problem

Physical Examination

*special problem, binary search, data structures

Laser Beams

*special problem, geometry, probabilities

A Battle Against a Dragon

*special problem, data structures, dp

Kotlinforces

*special problem, constructive algorithms, dp

Fix the String

*special problem, bitmasks, dp, greedy

Sweepstake

*special problem, brute force, constructive algorithms, implementation, math

Rhyme

*special problem, implementation

Epic Novel

*special problem, math

Sequence of Comparisons

*special problem

Palindromic Hamiltonian Path

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

Playoff Restoration

bitmasks, brute force, hashing, implementation, meet-in-the-middle

Inconvenient Pairs

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

Jury Meeting

combinatorics, math

Chess Tournament

constructive algorithms

Balanced Substring

implementation

One-Four Overload

2-sat, constructive algorithms, dfs and similar, dsu, graphs, implementation

Non-Decreasing Dilemma

data structures, divide and conquer, math

Expression Evaluation Error

constructive algorithms, greedy, implementation, math

Carrying Conundrum

bitmasks, combinatorics, dp, math

MEXor Mixup

bitmasks, greedy

Domino Disaster

implementation, strings

Xor-quiz

constructive algorithms, dp, interactive, math, number theory

Four Vertices

constructive algorithms, data structures, graphs, greedy, implementation, shortest paths

Points Movement

data structures, dp, greedy, implementation, sortings

Buds Re-hanging

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

Seating Arrangements (hard version)

data structures, greedy, implementation, sortings, two pointers

Seating Arrangements (easy version)

data structures, greedy, sortings

MAX-MEX Cut

bitmasks, constructive algorithms, dp, greedy

MIN-MEX Cut

bitmasks, constructive algorithms, dp, greedy

Median Maximization

binary search, greedy, math

Tubular Bells

interactive, math, number theory, probabilities

Rescue Niwen!

dp, greedy, string suffix structures, strings

Two Hundred Twenty One (hard version)

data structures, math

Two Hundred Twenty One (easy version)

data structures, dp, math

Rings

constructive algorithms, math

Scenes From a Memory

brute force, constructive algorithms, implementation, math, number theory

The Miracle and the Sleeper

greedy, math

Up the Strip (simplified version)

brute force, data structures, dp, math, number theory

Deep Down Below

binary search, greedy, sortings

Simply Strange Sort

brute force, implementation, sortings

Nearest Beautiful Number (hard version)

bitmasks, brute force, constructive algorithms, dfs and similar, dp, greedy

Nearest Beautiful Number (easy version)

binary search, bitmasks, brute force, constructive algorithms, dfs and similar, greedy

Polycarp and String Transformation

binary search, implementation, sortings, strings

Make a Power of Two

greedy, math, strings

Infinity Table

implementation, math

Who's Opposite?

math

Dislike of Threes

implementation

Mocha and Stars

combinatorics, dp, fft, math, number theory

Mocha and Diana (Hard Version)

brute force, constructive algorithms, dfs and similar, dsu, graphs, greedy, trees, two pointers

Mocha and Diana (Easy Version)

brute force, constructive algorithms, dsu, graphs, greedy, trees

Mocha and Hiking

constructive algorithms, graphs

Mocha and Red and Blue

dp, greedy

Mocha and Math

bitmasks, constructive algorithms, math

Strange Sort

data structures, sortings

Down Below

binary search, dfs and similar, graphs, greedy, meet-in-the-middle, shortest paths

Top-Notch Insertions

combinatorics, data structures

Bottom-Tier Reversals

constructive algorithms, greedy

Up the Strip

brute force, dp, math, number theory, two pointers

Charmed by the Game

brute force, math

Assiut Chess

brute force, constructive algorithms, interactive

Ezzat and Grid

data structures, dp, greedy

Moamen and XOR

bitmasks, combinatorics, dp, math, matrices