Petya and Spiders

bitmasks, dp, dsu

Running in Pairs

constructive algorithms, greedy, math

Tyndex.Brome

binary search, implementation

Rectangle Shrinking

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

Gaining Rating

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

Balanced Binary Search Trees

dp, math

Golden System

math, meet-in-the-middle

Circular Maze

brute force, dfs and similar, graphs, implementation

Point Ordering

constructive algorithms, geometry, interactive, math

Boxes and Balls

dp, implementation, math

Ideal Farm

constructive algorithms, math

Xum

bitmasks, constructive algorithms, math, matrices, number theory

Construct Matrix

constructive algorithms, math

Three Problems

*special problem, implementation

Power Tree

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

Cross-Language Program

*special problem, constructive algorithms

Continuous City

bitmasks, constructive algorithms

Expected diameter of a tree

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

Stepan and Vowels

*special problem, implementation, strings

Guide

Cyclic Shifts Sorting

brute force, constructive algorithms, implementation, sortings

Madhouse (Easy version)

brute force, constructive algorithms, interactive, math

Trucks and Cities

binary search, dp

Swapping Characters

brute force, hashing, implementation, strings

Sheldon and Ice Pieces

greedy

Guess That Car!

math, ternary search

Playing with Permutations

implementation, math

Multi-core Processor

implementation

Royal Questions

dsu, graphs, greedy

Laser

math

Minibuses on Venus (easy version)

combinatorics, divide and conquer, dp

Goodbye Souvenir

data structures, divide and conquer

Tree Folding

dfs and similar, dp, greedy, implementation, trees

Cardboard Box

data structures, greedy

Couple Cover

brute force, dp, number theory

Diameter Cuts

combinatorics, dfs and similar, dp, trees

Berland University

greedy, math

ucyhf

*special problem, brute force, implementation, number theory

First Digit Law

dp, math, probabilities

Rollbacks (Easy Version)

brute force, data structures, dfs and similar, trees

LuoTianyi and XOR-Tree

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

ZS and The Birthday Paradox

math, number theory, probabilities

Vittorio Plays with LEGO Bricks

dp, geometry

Tenzing and Tree

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

Sequence of Comparisons

*special problem

Leaf Sets

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

Constellation

implementation

Multiple Lamps

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

The Hidden Pair (Hard Version)

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

Bit Counting Sequence

Chain Chips

data structures, dp, matrices

Binary Tree on Plane

flows, trees

Good Subarrays (Hard Version)

binary search, data structures, dp, two pointers

Restore the Permutation by Sorted Segments

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

Mice problem

geometry, implementation, math, sortings

Coin Troubles

dp

Compartments

combinatorics, constructive algorithms, greedy, implementation

Different Subsets For All Tuples

combinatorics, math

Longest Array Deconstruction

data structures, divide and conquer, dp, sortings

Long Permutation

brute force, math, two pointers

Max History

combinatorics, math

Goods transportation

dp, flows, greedy

Drazil and Morning Exercise

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

Digits

*special problem

Defender of Childhood Dreams

bitmasks, constructive algorithms, divide and conquer

Legen...

data structures, dp, matrices, strings

Game with Stones

binary search, data structures, games, greedy

Intellectual Inquiry

dp, greedy, strings

Xorcerer's Stones

bitmasks, constructive algorithms, dp, trees

Move and Swap

dfs and similar, dp, greedy, trees

Frequency Problem (Hard Version)

data structures, greedy, two pointers

Alex and a TV Show

bitmasks, combinatorics, number theory

Sofa Thief

brute force, implementation

Break Up

dfs and similar, graphs

Mysterious Code

dp, strings

Bipartite Checking

data structures, dsu, graphs

Light Bulbs (Hard Version)

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

Pyramids

geometry, math

Little Elephant and Broken Sorting

dp, math, probabilities

Songwriter

greedy, two pointers

The Wall (medium)

combinatorics

Sequence of points

geometry, implementation, math

Simple Cycles Edges

dfs and similar, graphs, trees

Median on Segments (General Case Edition)

sortings

Reachable Strings

data structures, hashing, strings

Subway Innovation

greedy, math, two pointers

Double Happiness

brute force, math, number theory

Dividing Island

constructive algorithms

Optimal Polygon Perimeter

dp, geometry

Собери стол

constructive algorithms, sortings

Wizards and Minimal Spell

implementation, strings

Latin Square

math, matrices

Jordan Smiley

*special problem, dfs and similar, geometry, implementation

Lightsabers (medium)

binary search, two pointers

Swapping Problem

brute force, constructive algorithms, data structures, sortings

Nanosoft

binary search, data structures, dp, implementation

Something with XOR Queries

brute force, interactive, probabilities

Bug in Code

data structures, graphs, implementation, two pointers

BFS Trees

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

Removing Graph

brute force, dp, games, graphs, math