Nastya and CBS

brute force, data structures, hashing

Journey

data structures, divide and conquer, graphs, trees

No Monotone Triples

data structures

Dreamoon Likes Strings

constructive algorithms, data structures

Median Mountain Range

data structures

Treeland and Viruses

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

Battalion Strength

data structures, divide and conquer, probabilities

Concatenation with intersection

data structures, hashing, strings, two pointers

Sum of Prefix Sums

data structures, divide and conquer, geometry, trees

Cartesian Tree

data structures

Fedya the Potter Strikes Back

data structures, strings

LCC

data structures, math, matrices, probabilities

New Year and Social Network

data structures, graph matchings, graphs, math, trees

Number of Components

data structures

Colored Tree

data structures, trees

Tree Queries

data structures, probabilities, trees

Find String in a Grid

data structures, dp, strings, trees

Adilbek and the Watering System

data structures, greedy, sortings

Balanced Distribution

data structures, dp, greedy

Gardener Alex

binary search, data structures

Guarding warehouses

data structures, geometry

Feeling Good

bitmasks, data structures

Moving Walkways

data structures, greedy, math

Into Blocks (hard version)

data structures

Red Blue Tree

data structures, implementation, trees

Indie Album

data structures, dfs and similar, hashing, string suffix structures, strings, trees

Maximum Sine

binary search, data structures, number theory

Fedor Runs for President

data structures, dp, trees

The Awesomest Vertex

data structures, dfs and similar

Yet Another Partiton Problem

data structures, divide and conquer, dp, geometry, two pointers

Nauuo and Bug

data structures

Nauuo and ODT

data structures

Indecisive Taxi Fee

data structures, graphs, shortest paths

Tree Generator™

data structures, implementation, trees

Holy Diver

data structures

Double Tree

data structures, divide and conquer, shortest paths, trees

Matches Are Not a Child's Play

data structures, trees

Train Car Selection

data structures, greedy

Most Dangerous Shark

data structures, dp, two pointers

Isolation

data structures, dp

Secret Letters

data structures, dp, greedy

Niyaz and Small Degrees

data structures, dp, trees

Sasha and Algorithm of Silence's Sounds

data structures, trees

Sasha and a Very Easy Test

data structures, number theory

Sasha and a Patient Friend

binary search, data structures, implementation

Eels

data structures

Ehab and a weird weight formula

data structures, trees

Beautiful Matrix

combinatorics, data structures, dp

The Fair Nut and Amusing Xor

data structures

The Fair Nut's getting crazy

data structures, implementation

Max Mex

data structures, trees

Palindromic Magic

data structures, hashing, strings

Array Game

data structures, games

String Journey

data structures, dp, string suffix structures

Balls and Pockets

data structures

Detect Robots

data structures, strings

Take Metro

brute force, data structures, graphs

Distinctification

data structures, dsu, greedy

DFS

data structures

Speckled Band

data structures, divide and conquer, hashing, string suffix structures, strings

Summer Oenothera Exhibition

data structures

You Are Given a Tree

data structures, dp, trees

Security

data structures, string suffix structures

Intervals of Intervals

binary search, data structures, two pointers

Pisces

data structures, flows, trees

Raining season

data structures, divide and conquer, trees

The Tree

data structures

Store

data structures

Ants

2-sat, data structures, trees

Two-Paths

data structures, dp, trees

Good Subsegments

data structures

Prince's Problem

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

NN country

binary search, data structures, trees

Arkady and Rectangles

data structures

K Paths

combinatorics, data structures, dp, fft, math

Visible Black Areas

data structures, dsu, geometry, trees

Santa's Gift

data structures, trees

Shortest Path Queries

bitmasks, data structures, dsu, graphs

Iqea

data structures, dfs and similar, divide and conquer, dsu, shortest paths, trees

Escape Through Leaf

data structures, dp, geometry

Coins Exhibition

data structures, dp, math

May Holidays

data structures, trees

Upside Down

data structures, string suffix structures, strings, trees

Substrings in a String

bitmasks, brute force, data structures, string suffix structures, strings

Yet Another Maxflow Problem

data structures, flows, graphs

Welcome home, Chtholly

data structures, dsu

Tournament

data structures, graphs

Paths

data structures, number theory

Mahmoud and Ehab and the final stage

data structures, strings

Arkady and a Nobody-men

data structures, dfs and similar, trees

Nagini

binary search, data structures

Lada Malina

data structures, geometry

Caramel Clouds

data structures, dp, sortings

Red-Black Cobweb

data structures, divide and conquer, implementation, trees

Dirty Arkady's Kitchen

data structures, dp, graphs, shortest paths

Best Edge Weight

data structures, dfs and similar, graphs, trees

Karen and Cards

binary search, combinatorics, data structures, geometry

Hitchhiking in the Baltic States

data structures, dp

April Fools' Problem (hard)

binary search, data structures, flows

Cut the pie

binary search, data structures, geometry