Non-equal Neighbours

combinatorics, dp, math

Frequency Queries

data structures, dfs and similar, trees

Korney Korneevich and XOR (hard version)

binary search, brute force, dp, greedy, two pointers

Labyrinth

binary search, dsu, greedy

Managing Telephone Poles

data structures, geometry

Abnormal Permutation Pairs (easy version)

combinatorics, dp, fft, math

MEX Tree

combinatorics, dfs and similar, implementation, math, trees

Oolimry and Suffix Array

combinatorics, constructive algorithms, math

Love-Hate

bitmasks, brute force, dp, probabilities

Diameter Cuts

combinatorics, dfs and similar, dp, trees

Chaotic Merge

combinatorics, dp, math, strings

A-Z Graph

constructive algorithms, data structures, graphs, hashing

Fib-tree

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

Copy or Prefix Sum

combinatorics, data structures, dp, sortings

Useful Edges

graphs, shortest paths

Minimum Path

graphs, shortest paths

A Bit Similar

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

Plan of Lectures

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

Four Points

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

The Struggling Contestant

constructive algorithms, greedy

Long Permutation

brute force, math, two pointers

Graph Transpositions

dfs and similar, graphs, greedy, shortest paths

Complicated Computations

binary search, data structures, two pointers

Fruit Sequences

binary search, data structures, divide and conquer, dp, two pointers

Bubble Cup hypothesis

bitmasks, constructive algorithms, dp, math

Expected Damage

binary search, combinatorics, probabilities

Avoid Rainbow Cycles

data structures, dsu, graphs, greedy, sortings, trees

The Potion of Great Power

*special problem, 2-sat, binary search, data structures, graphs, interactive, sortings, two pointers

Reverse and Swap

binary search, bitmasks, data structures

Divide Square

data structures, geometry, implementation, sortings

Omkar and Landslide

binary search, constructive algorithms, data structures, greedy, math

Cyclic Shifts Sorting

brute force, constructive algorithms, implementation, sortings

Network Coverage

binary search, constructive algorithms, data structures, greedy

The Hidden Pair (Easy Version)

binary search, dfs and similar, graphs, interactive, shortest paths, trees

DeadLee

data structures, dfs and similar, greedy, implementation, sortings

Flying Sort (Hard Version)

binary search, data structures, dp, greedy, sortings, two pointers

Are You Fired?

constructive algorithms, data structures, greedy, implementation

Phoenix and Berries

brute force, dp, greedy, math

Restore the Permutation by Sorted Segments

brute force, constructive algorithms, data structures, greedy, implementation

Nastya and Unexpected Guest

dfs and similar, dp, graphs, shortest paths

Road to 1600

brute force, constructive algorithms

Drazil Likes Heap

constructive algorithms, data structures, greedy, implementation

Bombs

data structures, two pointers

Animal Observation (hard version)

data structures, dp, greedy

Prefix Enlightenment

dfs and similar, dsu, graphs

Madhouse (Easy version)

brute force, constructive algorithms, interactive, math

The Cake Is a Lie

constructive algorithms, data structures, dfs and similar, graphs

Apprentice Learning Trajectory

Beautiful Mirrors with queries

data structures, probabilities

Economic Difficulties

data structures, dfs and similar, dp, flows, graphs, trees

Tournament

brute force, dp, greedy

Make Them Similar

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

Regular Forestation

hashing, trees

Voting (Hard Version)

binary search, data structures, greedy

Running in Pairs

constructive algorithms, greedy, math

Sum Balance

bitmasks, dfs and similar, dp, graphs

Catowice City

2-sat, dfs and similar, graph matchings, graphs

Balanced Binary Search Trees

dp, math

Wrong Answer on test 233 (Hard Version)

combinatorics, math

Choose a Square

binary search, data structures, sortings

Xor Spanning Tree

divide and conquer, fft, graphs

Konrad and Company Evaluation

graphs

Palindromic Paths

implementation, interactive

You Are Given Some Strings...

brute force, string suffix structures, strings

Crossword Expert

combinatorics, dp, number theory, probabilities, two pointers

Subarray Sorting

data structures, sortings

Vus the Cossack and a Graph

dfs and similar, graphs, greedy, implementation

Daleks' Invasion (hard)

data structures, dsu, graphs, trees

Complete Mirror

constructive algorithms, dfs and similar, dp, hashing, implementation, trees

Ehab and the Big Finale

constructive algorithms, divide and conquer, graphs, implementation, interactive, trees

Vicky's Delivery Service

data structures, dsu, graphs, hashing

Magical Permutation

bitmasks, brute force, constructive algorithms, data structures, graphs, math

Neko and Flashback

constructive algorithms, dfs and similar, graphs

Palindrome XOR

dfs and similar, graphs

Hot is Cold

bitmasks, data structures, divide and conquer, implementation

Two Merged Sequences

dp, greedy

U2

geometry

Maximize Mex

flows, graph matchings, graphs

Cooperative Game

constructive algorithms, interactive, number theory

Greedy Subsequences

data structures, dp, trees

Morse Code

binary search, data structures, dp, hashing, sortings, string suffix structures, strings

Please, another Queries on Array?

bitmasks, data structures, divide and conquer, math, number theory

Sasha and Interesting Fact from Graph Theory

brute force, combinatorics, dp, math, trees

Vasya and Maximum Profit

binary search, constructive algorithms, data structures, dp, dsu

Vasya and Binary String

dp

Lunar New Year and a Recursive Sequence

math, matrices, number theory

Trucks and Cities

binary search, dp

Cookies

binary search, data structures, dfs and similar, dp, games, trees

Construct a tree

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

Lucky Tickets

divide and conquer, dp, fft

Vasya and Array

dp

Intersection of Permutations

data structures

New Year and the Acquaintance Estimation

binary search, data structures, graphs, greedy, implementation, math, sortings

New Year Presents

constructive algorithms, data structures

Minegraphed

constructive algorithms, graphs

King Kog's Reception

data structures

Ehab and a component choosing problem

dp, greedy, math, trees

The Fair Nut and Rectangles

data structures, dp, geometry

Petya and Graph

flows, graphs

Katya and Segments Sets

data structures, interactive, sortings