Make It One

bitmasks, combinatorics, dp, math, number theory, shortest paths

The Three Little Pigs

combinatorics, dp, fft, math

On the Bench

combinatorics, dp

Sky Full of Stars

combinatorics, math

AND Segments

bitmasks, combinatorics, data structures, dp, two pointers

Clues

combinatorics, graphs

Expected Destruction

combinatorics, dp, math, probabilities

Count Supersequences

combinatorics, dp, math

Ehab and the Expected GCD Problem

combinatorics, dp, math, number theory

Bash Plays with Functions

brute force, combinatorics, dp, number theory

Alex and a TV Show

bitmasks, combinatorics, number theory

Sports Betting

bitmasks, combinatorics, dp, graphs, math, probabilities

New Year and Castle Construction

combinatorics, geometry, math, sortings

Cow and Treats

binary search, combinatorics, dp, greedy, implementation, math

Levko and Strings

combinatorics, dp

Rare Coins

combinatorics, math, probabilities

Bags with Balls

combinatorics, dp, math, number theory

Curious Array

brute force, combinatorics, implementation, math

Maximum Reduction

combinatorics, data structures, math

K-Set Tree

combinatorics, dfs and similar, dp, math, trees

Ela Goes Hiking

combinatorics, dp, math, probabilities

Points

combinatorics, data structures, implementation, math, matrices

Coloring

combinatorics, constructive algorithms, implementation, math

The Top Scorer

combinatorics, dp, math, probabilities

DSU Master

combinatorics, dp, dsu, math

Small Permutation Problem (Hard Version)

combinatorics, dp, math

Max Sum Array

combinatorics, constructive algorithms, greedy, sortings

Baby Ehab Plays with Permutations

combinatorics, dp, math

Lexichromatography

combinatorics, dfs and similar, dsu, graphs, two pointers

Red-White Fence

combinatorics, fft

Tick, Tock

combinatorics, dfs and similar, dsu, graphs

Codeword

combinatorics, strings

Cowslip Collections

combinatorics, math, number theory

New Year and Entity Enumeration

bitmasks, combinatorics, dp, math

Misha and Palindrome Degree

binary search, combinatorics, implementation

Power or XOR?

bitmasks, combinatorics, math, number theory

Function Sum

brute force, combinatorics, dp, fft, math

Number Table

combinatorics

Minibuses on Venus (medium version)

combinatorics, divide and conquer, dp, matrices

Path Counting

combinatorics, dp

Electrical Efficiency

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

Igor and Interesting Numbers

brute force, combinatorics, dp, math

Sereja and Cinema

combinatorics, math

Cards

combinatorics, dp, math, number theory, probabilities

Crypto Lights

combinatorics, dp, math, probabilities

BFS Trees

combinatorics, dfs and similar, graphs, math, shortest paths, trees

Beautiful Bracket Sequence (easy version)

combinatorics, dp, probabilities

Emotional Fishermen

combinatorics, dp, math, two pointers

XOR Counting

bitmasks, combinatorics, dp, math

Mathematics Curriculum

brute force, combinatorics, dp, trees

Positions in Permutations

combinatorics, dp, math

Top-Notch Insertions

combinatorics, data structures

Destroy the Colony

combinatorics, dp, math

Omkar and Akmar

chinese remainder theorem, combinatorics, constructive algorithms, fft, games, geometry, math, meet-in-the-middle, string suffix structures

Mercenaries

bitmasks, brute force, combinatorics, dp, dsu, math, two pointers

New Year Garland

combinatorics, dp

Song of the Sirens

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

Balanced Domino Placements

combinatorics, dp

Counting Prefixes

combinatorics, constructive algorithms, dp, implementation, math

Conditional Mix

combinatorics, dp, math

Serval and Bonus Problem

combinatorics, dp, math, probabilities

Bingo

bitmasks, combinatorics, dp, math, probabilities

Number Challenge

combinatorics, dp, implementation, math, number theory

Find a car

combinatorics, divide and conquer, dp

Playlist for Polycarp (hard version)

combinatorics, dp

Timber

combinatorics, dp, fft, math

Count Voting

combinatorics, dp, math

Tree Coloring

combinatorics, divide and conquer, fft

An unavoidable detour for home

combinatorics, dp, graphs, shortest paths

Pairs of Paths

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

Fancy Arrays

combinatorics, dp, math, matrices

Tree Sum

combinatorics, math, trees

Triangles

combinatorics, dp

Sum of Matchings

brute force, combinatorics, constructive algorithms, dfs and similar, graph matchings, greedy, math

Gifts

combinatorics, dp, math, probabilities

Dominoes

combinatorics, flows, graph matchings, greedy

Thoroughly Bureaucratic Organization

binary search, combinatorics

Interval-Free Permutations

combinatorics

Ksenia and Combinatorics

combinatorics, dp

Card Guessing

combinatorics, dp, probabilities

Star Trek

*special problem, combinatorics, dfs and similar, dp, games, graphs, matrices, trees

Vowels

combinatorics, divide and conquer, dp

Partitions

combinatorics, math, number theory

Cowmpany Cowmpensation

combinatorics, dp, math, trees

Sereja and Intervals

combinatorics, dp

Two Arrays

bitmasks, brute force, combinatorics, greedy, hashing, math, two pointers

Good Contest

combinatorics, dp, probabilities

Clusterization Counting

combinatorics, dp, dsu, fft, graphs, trees

Majority

combinatorics, dp, math, strings

Region Separation

combinatorics, dp, number theory, trees

Abnormal Permutation Pairs (hard version)

combinatorics, dp, fft, math

Distinct Paths

brute force, combinatorics

Balanced Subsequences

combinatorics, dp, math

Bracket Insertion

combinatorics, dp, math, trees

Graph Coloring (easy version)

combinatorics, dp, graphs

Chiori and Doll Picking (easy version)

bitmasks, brute force, combinatorics, math

Maximums and Minimums

combinatorics, data structures, divide and conquer, number theory

Matrix Rank (Easy Version)

brute force, combinatorics, dp, math, matrices

String Counting

combinatorics, dp, fft, math

Occurrences

combinatorics, dfs and similar, dp, dsu, fft, graphs