The Humanoid

brute force, dp, sortings

Make It Round

brute force, number theory

Decent Division

constructive algorithms, data structures

Tick, Tock

combinatorics, dfs and similar, dsu, graphs

Range = √Sum

binary search, brute force, constructive algorithms, math, two pointers

Almost All Multiples

greedy, number theory

Minecraft Series

brute force, two pointers

N Machines

binary search, brute force, greedy

The Beach

constructive algorithms, dfs and similar, graphs, shortest paths

Wish I Knew How to Sort

dp, math, probabilities

Factorial Divisibility

math, number theory

Make Nonzero Sum (hard version)

constructive algorithms, dp, greedy

BinaryStringForces

constructive algorithms, data structures, dp

Doping

combinatorics, dp, math

Majority

combinatorics, dp, math, strings

Bracket Cost

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

Count GCD

combinatorics, math, number theory

Complementary XOR

constructive algorithms, implementation

Distance to the Path

data structures, dfs and similar, trees

Cactus Wall

constructive algorithms, dfs and similar, graphs, shortest paths

Counting Arrays

combinatorics, dp, math, number theory

Number Game

binary search, data structures, games, greedy, implementation

Circular Xor Reversal

bitmasks, constructive algorithms

Yet Another Array Counting Problem

binary search, data structures, divide and conquer, dp, flows, math, trees

ConstructOR

bitmasks, chinese remainder theorem, combinatorics, constructive algorithms, math, number theory

Zero-Sum Prefixes

brute force, data structures, dp, greedy, implementation

Diverse Substrings

brute force, implementation, strings

List Generation

combinatorics, dp, math

Yet Another Problem

binary search, bitmasks, constructive algorithms, data structures

Olympiad Training

binary search, data structures, dp, flows, geometry, implementation, sortings

Kazaee

data structures, hashing, probabilities

Joking (Hard Version)

dp, interactive

Joking (Easy Version)

binary search, constructive algorithms, interactive, ternary search

Paths on the Tree

dfs and similar, dp, greedy, sortings, trees

MEX vs MED

math, two pointers

Divisible Numbers (hard version)

brute force, math, number theory

Divisible Numbers (easy version)

brute force, math, number theory

Antifibonacci Cut

bitmasks, combinatorics, constructive algorithms, data structures, dp, hashing, math

Intersection and Union

data structures, dp, matrices, probabilities

FTL

binary search, dp

Problem with Random Tests

brute force, dp, greedy, probabilities

Orray

bitmasks, brute force, greedy, math, sortings

Smaller

constructive algorithms, greedy, strings

Kirill and Company

bitmasks, brute force, dfs and similar, dp, flows, graphs, shortest paths

Multi-Colored Segments

binary search, data structures, math, sortings

Sending a Sequence Over the Network

dp

Arranging Crystal Balls

data structures, divide and conquer, divide and conquer, dp, geometry, graphs, number theory

MEX Tree Manipulation

data structures, trees

Dangerous Laser Power

constructive algorithms, dsu, sortings

Conditional Mix

combinatorics, dp, math

Hanging Hearts

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

Knowledge Cards

constructive algorithms, data structures

Bricks and Bags

constructive algorithms, games, greedy, sortings

Keyboard Design

bitmasks, data structures, dp, string suffix structures, strings

Cleaning Robot

bitmasks, dp

Reset K Edges

binary search, data structures, dfs and similar, graphs, greedy, trees

Card Game

combinatorics, constructive algorithms, dp, games

Palindrome Addicts

data structures, strings

Anti-Increasing Addicts

constructive algorithms, dp, greedy, math

Connectivity Addicts

constructive algorithms, dsu, graphs, greedy, interactive, shortest paths, trees

Balance Addicts

combinatorics, dp, math, two pointers

Permutation Addicts

constructive algorithms, data structures, dfs and similar, dsu, graphs, trees

Even Number Addicts

dp, games, greedy, math

Ela Takes Dancing Class

binary search, data structures

Ela and Prime GCD

constructive algorithms, math, number theory

Ela Goes Hiking

combinatorics, dp, math, probabilities

Ela and the Wiring Wizard

brute force, dp, graphs, greedy, implementation, shortest paths

Ela and Crickets

constructive algorithms, games, implementation, math

Swap and Take

dp, greedy

Equal Binary Subsequences

constructive algorithms, geometry, greedy, implementation, strings

Good Subarrays (Hard Version)

binary search, data structures, dp, two pointers

Pebbles and Beads

data structures, geometry

House Planning

constructive algorithms, data structures, graph matchings, greedy

Meta-set

brute force, combinatorics, data structures, hashing, math

Phase Shift

dfs and similar, dsu, graphs, greedy, implementation, strings

Zeros and Ones

bitmasks, divide and conquer, dp, math

Rectangular Congruence

constructive algorithms, number theory

Slime Escape

data structures, dp, greedy, two pointers

Conveyor

constructive algorithms, dp, math

Zero-One (Hard Version)

dp, greedy

Zero-One (Easy Version)

constructive algorithms, greedy, math

Location

data structures, dp, math, number theory

Balance (Hard version)

brute force, data structures, number theory

Balance (Easy version)

brute force, data structures, implementation, number theory

Sheikh (Hard Version)

binary search, bitmasks, brute force, greedy, implementation, two pointers

Sheikh (Easy version)

binary search, bitmasks, greedy, two pointers

Function Sum

brute force, combinatorics, dp, fft, math

Graph Cost

dp, greedy, math, number theory

Valiant's New Map

binary search, brute force, data structures, dp, two pointers

Even Subarrays

bitmasks, brute force, hashing, math, number theory

Almost Sorted

bitmasks, data structures, dp

Maximums and Minimums

combinatorics, data structures, divide and conquer, number theory

Prefixes and Suffixes

constructive algorithms, strings, two pointers

Meeting on the Line

binary search, geometry, greedy, implementation, math, ternary search

Cut Substrings

combinatorics, dp, hashing, strings, two pointers

Kirei and the Linear Function

hashing, math

Guess the Cycle Size

interactive, probabilities

Illumination

binary search, bitmasks, brute force, combinatorics, dp, math, two pointers

Fishermen

flows, graph matchings, greedy

Red-Black Pepper

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