Team Players

combinatorics

Isomorphic Strings

hashing, strings

Pencils and Boxes

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

Sand Fortress

binary search, constructive algorithms, math

Liebig's Barrels

greedy

NN country

binary search, data structures, trees

Arkady and Rectangles

data structures

Elevator

dp, graphs, shortest paths

XOR-pyramid

dp

Finite or not?

implementation, math

The Meeting Place Cannot Be Changed

dfs and similar, graphs

Billiard

geometry, number theory

Shark

brute force, data structures, dsu, trees

Cut 'em all!

dfs and similar, dp, graphs, greedy, trees

K Paths

combinatorics, data structures, dp, fft, math

Magic multisets

data structures

Round Marriage

binary search, graph matchings, greedy

Addition on Segments

bitmasks, data structures, divide and conquer, dp

Bookshelves

bitmasks, dp, greedy

Useful Decomposition

implementation, trees

Cactus to Tree

dp, graphs, trees

The Number Games

data structures, greedy, trees

Perfect Groups

dp, math, number theory

Posterized

games, greedy

Marlin

constructive algorithms

Kuro and Topological Parity

dp

Kuro and GCD and XOR and SUM

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

Kuro and Walking Route

dfs and similar, trees

Treasure Hunt

greedy

Petya's Exams

greedy, implementation, sortings

Mentors

binary search, data structures, implementation

Bus Video System

combinatorics, math

Almost Arithmetic Progression

brute force, implementation, math

Consecutive Subsequence

dp

Cyclic Components

dfs and similar, dsu, graphs

Divide by three, multiply by two

dfs and similar, math, sortings

Minimal k-covering

flows, graphs

Well played!

greedy, sortings

Degree Set

constructive algorithms, graphs, implementation

Nested Segments

greedy, implementation, sortings

Hag's Khashba

geometry

Ghosts

geometry, math

Valhalla Siege

binary search

Short Code

data structures, dp, greedy, strings, trees

Single-use Stones

binary search, flows, greedy, two pointers

Greedy Arkady

math

Circles of Waiting

math

Frequency of String

hashing, string suffix structures, strings

Cutting Rectangle

brute force, math, number theory

Destruction of a Tree

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

Alternating Sum

math, number theory

Visible Black Areas

data structures, dsu, geometry, trees

Simple Cycles Edges

dfs and similar, graphs, trees

Byteland, Berland and Disputed Cities

constructive algorithms, greedy

Merge Equals

data structures, implementation

Make a Square

brute force, implementation, math

Partitions

combinatorics, math, number theory

k-substrings

binary search, hashing, string suffix structures

Tufurama

data structures

Pair Of Lines

geometry

Chessboard

bitmasks, brute force, implementation

Santa's Gift

data structures, trees

Bandit Blues

combinatorics, dp, fft, math

Pathwalks

data structures, dp, graphs

Alternating Tree

combinatorics, dfs and similar, divide and conquer, dp, probabilities, trees

Full Binary Tree Queries

brute force, implementation, trees

Subsequence Counting

bitmasks, constructive algorithms, greedy, implementation

Minimize the error

data structures, greedy, sortings

Mahmoud and Ehab and yet another xor task

bitmasks, dp, math, matrices

Mahmoud and Ehab and the xor-MST

bitmasks, dp, graphs, implementation, math

Mahmoud and Ehab and another array construction task

constructive algorithms, greedy, math, number theory

Mahmoud and Ehab and the wrong algorithm

constructive algorithms, trees

Lightsabers (hard)

fft

Lightsabers (medium)

binary search, two pointers

Lightsabers (easy)

implementation

Guard Duty (hard)

geometry

Guard Duty (medium)

binary search, dp, greedy, sortings

Guard Duty (easy)

brute force, geometry, greedy, math

Hyperspace Jump (hard)

Hyperspace Jump (easy)

expression parsing, math

Encryption (hard)

data structures, dp

Encryption (medium)

dp

Maximum Control (medium)

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

Death Stars (hard)

Death Stars (medium)

hashing, strings

Death Stars (easy)

implementation

Heaps

dp, trees

Icicles

Scissors

brute force, strings

Sad powers

binary search, math, number theory

Not simply beatiful strings

implementation

Yet Another String Matching Problem

fft, math

Path Counting

combinatorics, dp

Castle Defense

binary search, data structures, greedy, two pointers

Runner's Problem

dp, matrices, sortings

Water Taps

binary search, greedy, sortings

Fight Against Traffic

dfs and similar, graphs, shortest paths

Matrix Walk

implementation

String Typing

implementation, strings

Puzzling Language

constructive algorithms