New Year and Original Order

dp, math

Sereja and Table

bitmasks, greedy

Radio stations

binary search, data structures

Anton and School

bitmasks, constructive algorithms, implementation, math

Laser

math

Rotating Substrings

dp, strings

Nikita and stack

data structures

LRU

bitmasks, dp, math, probabilities

Rebrending

brute force, data structures, divide and conquer, implementation

XOR Triangle

bitmasks, brute force, constructive algorithms, dp, greedy, math

Felicity's Big Secret Revealed

bitmasks, dp

Wallpaper

implementation, math

Three Problems

*special problem, implementation

Sasha and Interesting Fact from Graph Theory

brute force, combinatorics, dp, math, trees

Three Pieces

dfs and similar, dp, shortest paths

PolandBall and Gifts

bitmasks, dp, greedy

Dima and Trap Graph

binary search, data structures, dfs and similar, dsu, shortest paths, two pointers

Tree-String Problem

*special problem, dfs and similar, hashing, strings

Petya and Spiders

bitmasks, dp, dsu

The Struggling Contestant

constructive algorithms, greedy

Close Vertices

data structures, divide and conquer, trees

Gaining Rating

binary search, greedy, implementation, math, sortings, two pointers

Longest Array Deconstruction

data structures, divide and conquer, dp, sortings

Bash Plays with Functions

brute force, combinatorics, dp, number theory

Lucky Permutation

brute force, combinatorics, number theory

Boring Partition

constructive algorithms

Construct Matrix

constructive algorithms, math

Rectangle Shrinking

binary search, brute force, data structures, greedy, implementation, two pointers

Xum

bitmasks, constructive algorithms, math, matrices, number theory

Nanosoft

binary search, data structures, dp, implementation

Nastya and King-Shamans

binary search, data structures

Bathroom terminal

implementation

Ideal Farm

constructive algorithms, math

Running in Pairs

constructive algorithms, greedy, math

Balanced Binary Search Trees

dp, math

Power Tree

dfs and similar, dp, dsu, graphs, greedy, trees

Tyndex.Brome

binary search, implementation

Point Ordering

constructive algorithms, geometry, interactive, math

Golden System

math, meet-in-the-middle

Boxes and Balls

dp, implementation, math

Cross-Language Program

*special problem, constructive algorithms

Circular Maze

brute force, dfs and similar, graphs, implementation

Guide

Cyclic Shifts Sorting

brute force, constructive algorithms, implementation, sortings

Trucks and Cities

binary search, dp

Expected diameter of a tree

binary search, brute force, dfs and similar, dp, sortings, trees

Continuous City

bitmasks, constructive algorithms

Stepan and Vowels

*special problem, implementation, strings

Madhouse (Easy version)

brute force, constructive algorithms, interactive, math

Sheldon and Ice Pieces

greedy

Swapping Characters

brute force, hashing, implementation, strings

LuoTianyi and XOR-Tree

data structures, dfs and similar, dp, dsu, greedy, trees

Multi-core Processor

implementation

Guess That Car!

math, ternary search

Cardboard Box

data structures, greedy

Minibuses on Venus (easy version)

combinatorics, divide and conquer, dp

Playing with Permutations

implementation, math

Royal Questions

dsu, graphs, greedy

Berland University

greedy, math

Goodbye Souvenir

data structures, divide and conquer

Bit Counting Sequence

Rollbacks (Easy Version)

brute force, data structures, dfs and similar, trees

Chain Chips

data structures, dp, matrices

Tree Folding

dfs and similar, dp, greedy, implementation, trees

Couple Cover

brute force, dp, number theory

ucyhf

*special problem, brute force, implementation, number theory

Multiple Lamps

bitmasks, brute force, constructive algorithms, math, number theory

Diameter Cuts

combinatorics, dfs and similar, dp, trees

The Hidden Pair (Hard Version)

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

Vittorio Plays with LEGO Bricks

dp, geometry

First Digit Law

dp, math, probabilities

Tenzing and Tree

dfs and similar, greedy, shortest paths, sortings, trees

ZS and The Birthday Paradox

math, number theory, probabilities

Sequence of Comparisons

*special problem

Reachable Strings

data structures, hashing, strings

Counting Is Fun (Easy Version)

brute force, combinatorics, dp, math

Leaf Sets

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

Constellation

implementation

Good Subarrays (Hard Version)

binary search, data structures, dp, two pointers

Binary Tree on Plane

flows, trees

Restore the Permutation by Sorted Segments

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

Mice problem

geometry, implementation, math, sortings

Different Subsets For All Tuples

combinatorics, math

Coin Troubles

dp

Compartments

combinatorics, constructive algorithms, greedy, implementation

Max History

combinatorics, math

Long Permutation

brute force, math, two pointers

Goods transportation

dp, flows, greedy

Drazil and Morning Exercise

dfs and similar, dp, dsu, trees, two pointers

Defender of Childhood Dreams

bitmasks, constructive algorithms, divide and conquer

Digits

*special problem

Break Up

dfs and similar, graphs

Legen...

data structures, dp, matrices, strings

Light Bulbs (Hard Version)

combinatorics, data structures, dfs and similar, dp, graphs, hashing

Game with Stones

binary search, data structures, games, greedy

Mysterious Code

dp, strings

Intellectual Inquiry

dp, greedy, strings

Xorcerer's Stones

bitmasks, constructive algorithms, dp, trees

Bipartite Checking

data structures, dsu, graphs

Sequence of points

geometry, implementation, math