Enormous XOR

bitmasks, constructive algorithms, greedy, math, strings, two pointers

Almost Fault-Tolerant Database

brute force, constructive algorithms, dfs and similar, greedy, implementation

Ruler Of The Zoo

brute force, data structures

Yuezheng Ling and Dynamic Tree

data structures, trees

Switch and Flip

constructive algorithms, graphs, math

Magnets

binary search, constructive algorithms, interactive

Fib-tree

brute force, dfs and similar, divide and conquer, number theory, trees

Flower Shop

*special problem, data structures, fft, math

Demonic Invasion

*special problem, flows

Build From Suffixes

*special problem, combinatorics, data structures

Painting Numbers

*special problem, data structures, greedy, number theory

String Counting

combinatorics, dp, fft, math

Ones

dp, greedy, shortest paths

Pairs of Paths

combinatorics, data structures, dfs and similar, dp, trees

Copy or Prefix Sum

combinatorics, data structures, dp, sortings

Move and Swap

dfs and similar, dp, greedy, trees

Exam

data structures, string suffix structures, trees

Vabank

binary search, interactive

Useful Edges

graphs, shortest paths

AB Tree

dp, greedy, trees

Sorting Books

data structures, dp, greedy

School Clubs

dp, fft, math, number theory, probabilities

Odd Mineral Resource

binary search, bitmasks, brute force, data structures, probabilities, trees

Continuous City

bitmasks, constructive algorithms

Nezzar and Chocolate Bars

combinatorics, fft, math, probabilities

Nezzar and Tournaments

data structures, greedy

Nezzar and Hidden Permutations

constructive algorithms, dfs and similar, graphs

Minimum Difference

data structures, hashing, sortings, two pointers

Lanterns

binary search, data structures, dp

1 2 3 4 ...

dp, math, matrices

What Is It?

constructive algorithms, greedy

Tiles

combinatorics, dp, fft, math

Strange Set

flows, math

Minimum Path

graphs, shortest paths

Strange Covering

divide and conquer

Strange Permutation

binary search, combinatorics, data structures, dp, graphs, implementation, two pointers

Strange Shuffle

binary search, brute force, constructive algorithms, interactive

Power Sockets

binary search, data structures, greedy

A Bit Similar

bitmasks, brute force, hashing, string suffix structures, strings, two pointers

Prime Divisors Selection

binary search, greedy, math, number theory

Plane Tiling

geometry, implementation, math

Hobbits

binary search, geometry

Bakery

data structures, dsu

Distinctive Roots in a Tree

data structures, dfs and similar, dp, trees

The Riddle of the Sphinx

binary search, data structures, data structures, interactive

Finding satisfactory solutions

combinatorics, dp, graphs, greedy, math

Song of the Sirens

combinatorics, divide and conquer, hashing, math, string suffix structures, strings

My Beautiful Madness

data structures, trees

Max Correct Set

bitmasks, dp, math

Plan of Lectures

constructive algorithms, dfs and similar, dsu, graphs, implementation, sortings, trees

Mathematical Expression

constructive algorithms, dp, greedy

Range Diameter Sum

data structures, trees

Nim Shortcuts

data structures, games

Flip and Reverse

data structures, graphs, greedy

Latin Square

math, matrices

XOR-ranges

dp, greedy

Forbidden Value

data structures, dp

String and Operations

dp, greedy

Four Points

brute force, constructive algorithms, flows, geometry, greedy, implementation, math, ternary search

Even Harder

dp

Game On Tree

data structures, dfs and similar, greedy, trees

Divide Powers

constructive algorithms, greedy

Two Editorials

brute force, dp, greedy, sortings, two pointers

Nullify The Matrix

constructive algorithms, games

Multithreading (Hard Version)

combinatorics, implementation, math

Multithreading (Easy Version)

combinatorics, fft, math

Communism

bitmasks, dp, trees

The Struggling Contestant

constructive algorithms, greedy

Capitalism

constructive algorithms, dfs and similar, graphs, shortest paths

Line Distance

binary search, data structures, geometry

Long Recovery

constructive algorithms, dfs and similar

Frequency Problem (Hard Version)

data structures, greedy, two pointers

Frequency Problem (Easy Version)

data structures, greedy

Finding the Vertex

brute force, dfs and similar, dp, interactive, trees

Rectangular Polyline

constructive algorithms, dp, geometry

Team-Building

data structures, dfs and similar, dsu, graphs

Long Permutation

brute force, math, two pointers

Differentiating Games

games, interactive

Black, White and Grey Tree

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

Sum

data structures, divide and conquer, dp, greedy

Graph Transpositions

dfs and similar, graphs, greedy, shortest paths

Cheat and Win

bitmasks, data structures, games, trees

INOI Final Contests

combinatorics, dp, fft

Greedy Shopping

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

Graph Subset Problem

constructive algorithms, data structures, graphs

Olha and Igor

interactive, probabilities, trees

Yurii Can Do Everything

binary search, bitmasks, brute force, constructive algorithms, divide and conquer, two pointers

Death DBMS

data structures, string suffix structures, strings, trees

Emotional Fishermen

combinatorics, dp, math, two pointers

Sum Over Subsets

combinatorics, math, number theory

Complicated Computations

binary search, data structures, two pointers

A Convex Game

dsu, games

Zero-XOR Array

*special problem, dp

Cyclic Shifts

*special problem, strings

Rogue-like Game

*special problem, brute force, greedy, two pointers

Yet Another DAG Problem

bitmasks, dfs and similar, dp, flows, graphs, math

Realistic Gameplay

dp, greedy

Rotary Laser Lock

binary search, interactive

Lucky Numbers (Hard Version)

dp, greedy

Lucky Numbers (Easy Version)

dp, greedy