Hongcow's Game

bitmasks, divide and conquer, interactive

Chip 'n Dale Rescue Rangers

binary search, geometry, math

Array Beauty

dp

Railguns

brute force, dfs and similar, dp, graphs

K and Medians

constructive algorithms, greedy, math

Isomorphic Strings

hashing, strings

Genetic Engineering

implementation, two pointers

Sereja and the Arrangement of Numbers

graphs, greedy, sortings

Node Pairs

dp, graphs, math, number theory

Permutation recovery

constructive algorithms, data structures, dfs and similar, graphs, greedy, math, sortings

Edge Reverse

binary search, dfs and similar, graphs, trees

Big Data

*special problem

Towers

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

Warrior and Archer

games

Vasya and Magic Matrix

dp, math, probabilities

Anya's Simultaneous Exhibition

constructive algorithms, graphs, greedy, interactive, sortings

The Maximum Subtree

dfs and similar, dp, graphs, trees

Game

dfs and similar, greedy

Great Grids

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

Phoenix and Earthquake

constructive algorithms, dfs and similar, dsu, graphs, greedy, trees

Hamiltonian Spanning Tree

dfs and similar, dp, graph matchings, greedy, trees

The Maths Lecture

dp, implementation

Kuro and GCD and XOR and SUM

binary search, bitmasks, brute force, data structures, dp, dsu, greedy, math, number theory, strings, trees

Full Binary Tree Queries

brute force, implementation, trees

Unsorting Array

brute force, sortings

List Of Integers

binary search, bitmasks, brute force, combinatorics, math, number theory

Colorful Points

data structures, greedy, implementation

Evolution of Weasels

greedy, implementation, strings

Nearest Leaf

data structures, trees

Greedy Shopping

binary search, data structures, divide and conquer, greedy, implementation

Door Frames

greedy, implementation

Phone Number

dp

Spyke Chatting

implementation

Light Bulbs (Easy Version)

brute force, combinatorics, dfs and similar, dp, dsu, graphs, math, trees

Hemose on the Tree

bitmasks, constructive algorithms, dfs and similar, trees

Jamie and Binary Sequence (changed after round)

bitmasks, greedy, math

String Set Queries

brute force, data structures, hashing, interactive, string suffix structures, strings

The Beach

constructive algorithms, dfs and similar, graphs, shortest paths

Subtree Minimum Query

data structures, trees

Maximum Monogonosity

brute force, dp, math

Delete a Segment

brute force, constructive algorithms, data structures, dp, graphs, sortings, trees, two pointers

K Integers

binary search, data structures

Network Mask

*special problem, bitmasks, brute force, implementation

Numbers

combinatorics, dp

Train Maintenance

brute force, data structures, implementation

Restore Cube

brute force, geometry

A-Z Graph

constructive algorithms, data structures, graphs, hashing

IT Restaurants

dfs and similar, dp, trees

Points

implementation, math

Yet Another Inversions Problem

combinatorics, data structures, dp, implementation, math, number theory

Earth Wind and Fire

constructive algorithms, greedy, math, sortings, two pointers

Greg and Friends

combinatorics, dp, graphs, shortest paths

Chopping Carrots (Hard Version)

brute force, constructive algorithms, data structures, dp, greedy, math, number theory, two pointers

Maximize Mex

flows, graph matchings, graphs

Mahmoud and Ehab and the binary string

binary search, divide and conquer, interactive

Substitutes in Number

dp

Ordering Pizza

binary search, sortings, ternary search

GukiZ and GukiZiana

binary search, data structures, implementation

Insertion Sort

data structures, dp, implementation, math

Red-Black Pepper

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

DIY Garland

constructive algorithms, greedy, trees

Alice and the Doll

brute force, data structures, greedy, implementation

You Are Given a Tree

data structures, dp, trees

Desk Disorder

combinatorics, dfs and similar, dsu, graphs, trees

On the Bench

combinatorics, dp

Hockey

implementation, strings

Tree Modification

brute force, constructive algorithms, dfs and similar, graph matchings, graphs, trees

Sum Queries?

data structures, greedy, implementation, math

Tree

binary search, dp, trees

President and Roads

dfs and similar, graphs, hashing, shortest paths

Disposition

constructive algorithms, math

Professor GukiZ and Two Arrays

binary search, two pointers

Quantifier Question

dfs and similar, dp, graphs, math

Grid

brute force

Small Permutation Problem (Easy Version)

brute force, combinatorics, dp, math

Arthur and Walls

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

Sky Full of Stars

combinatorics, math

Death Stars (easy)

implementation

Bots

combinatorics, dp, math, number theory

Scrambled

*special problem, implementation

Distributing Parts

greedy, sortings

AmShZ and G.O.A.T.

binary search, brute force, greedy, implementation, math

Sasha and the Wedding Binary Search Tree

brute force, combinatorics, data structures, dfs and similar, math, trees

Average Score

greedy, math, sortings

Bulls and Cows

brute force, implementation

Bear and Up-Down

brute force, implementation

Ann and Books

data structures, flows, hashing

Minimal Diameter Forest

constructive algorithms, dfs and similar, greedy, trees

Mister B and PR Shifts

data structures, implementation, math

Artem and Array

data structures, greedy

Flawed Flow

constructive algorithms, flows, graphs, greedy

Vlad and the Nice Paths (hard version)

binary search, combinatorics, data structures, dp, math, two pointers

Camels

dp

Network Coverage

binary search, constructive algorithms, data structures, greedy

Diana and Liana

greedy, implementation, two pointers

Changing Brackets

constructive algorithms, data structures, dp, greedy

Lucky Array

data structures

International Olympiad

constructive algorithms, greedy, implementation, math

Fairy

dfs and similar, divide and conquer, dsu

Non-Intersecting Subpermutations

combinatorics, dp, implementation, math