Half-sum

brute force, divide and conquer, greedy

Toy Machine

constructive algorithms, games, implementation

Similar Polynomials

combinatorics, math

Fish Graph

brute force, constructive algorithms, dfs and similar, graphs

Almost Increasing Subsequence

binary search, data structures, greedy

Grid Reconstruction

constructive algorithms, greedy

Ian Visits Mary

constructive algorithms, geometry, number theory

OH NO1 (-2-3-4)

constructive algorithms, graphs, math

Bosco and Particle

dp, math, number theory, strings

XOR Counting

bitmasks, combinatorics, dp, math

Between

constructive algorithms, dfs and similar, graphs, greedy

Sum Graph

brute force, constructive algorithms, graphs, implementation, interactive, shortest paths, trees

Ian and Array Sorting

greedy, math

Communication Towers

brute force, divide and conquer, dsu

Chain Chips

data structures, dp, matrices

Balancing Weapons

binary search, brute force, data structures, math, two pointers

Search in Parallel

constructive algorithms, greedy, sortings

Long Legs

brute force, math

Coins

implementation, math

Vlad and the Nice Paths (hard version)

binary search, combinatorics, data structures, dp, math, two pointers

Vlad and the Nice Paths (easy version)

combinatorics, dp, math

Is It Flower?

dfs and similar, graphs, implementation

Living Sequence

binary search, dp, math, number theory

Umka and a Long Flight

constructive algorithms, implementation, math

Restore the Array

constructive algorithms, greedy

Conveyor Belts

implementation, math

Insert Digit

greedy, math, strings

Last Number

combinatorics, math

The Maximum Prefix

dp

M-tree

data structures, math, sortings, trees

Monsters

brute force, data structures, dfs and similar, dsu, graphs, greedy

Climbing the Tree

binary search, math

Make It Permutation

brute force, greedy, sortings

Candies

constructive algorithms, math, number theory

Beautiful Sequence

brute force, greedy

Prediction

combinatorics, dp, math

Traveling in Berland

binary search, data structures, graphs, greedy, implementation

Two Tanks

binary search, dp, implementation, math

Binary String Sorting

constructive algorithms, greedy

Sum on Subarrays

constructive algorithms, greedy, math

Points on Plane

binary search, greedy, math

Garland

implementation

Minibuses on Venus (hard version)

brute force, combinatorics, dp, math

Minibuses on Venus (medium version)

combinatorics, divide and conquer, dp, matrices

Minibuses on Venus (easy version)

combinatorics, divide and conquer, dp

Petya, Petya, Petr, and Palindromes

binary search, brute force, data structures, two pointers

Unlucky Numbers

brute force, dp, greedy, implementation

Playing in a Casino

math, sortings

Lucky Numbers

brute force, implementation

Subsequence Addition (Hard Version)

bitmasks, dp, greedy, implementation, sortings

Subsequence Addition (Easy Version)

brute force, data structures, dp, greedy, implementation, sortings

Bouncy Ball

brute force, dfs and similar, implementation

Interview

binary search, implementation, interactive

Odd Queries

data structures, implementation

Find and Replace

greedy, implementation, strings

Grab the Candies

greedy

Plus or Minus

implementation

GCD Master (hard version)

greedy, math, sortings

GCD Master (easy version)

greedy, math, number theory, sortings

Tree Master

brute force, data structures, dfs and similar, trees

DSU Master

combinatorics, dp, dsu, math

Sequence Master

brute force, constructive algorithms, math

Mex Master

constructive algorithms, greedy

Walking Master

geometry, greedy, math

Survival of the Weakest (hard version)

greedy, math, sortings, two pointers

Survival of the Weakest (easy version)

binary search, brute force, implementation, math, sortings

There Should Be a Lot of Maximums

brute force, data structures, dfs and similar, dp, trees, two pointers

A Wide, Wide Graph

dfs and similar, dp, graphs, greedy, trees

Place for a Selfie

binary search, data structures, geometry, math

The String Has a Target

greedy, strings

We Need the Zero

bitmasks, brute force

Code Lock

bitmasks, dp

Flow Control

data structures, dsu, implementation

Approximate Diameter

binary search, divide and conquer, graphs, shortest paths

Routing

bitmasks, brute force, dfs and similar, dp, graphs

Accommodation

brute force, dp, greedy, implementation

Pull Your Luck

brute force, greedy, math, number theory

Vaccination

greedy, implementation

Lame King

greedy, math

Settlement of Guinea Pigs

greedy, implementation, math

Likes

greedy, implementation

A task for substrings

data structures, string suffix structures, strings

Another n-dimensional chocolate bar

dp, math, meet-in-the-middle, number theory

Gasoline prices

data structures, divide and conquer, dsu, hashing, trees

The way home

binary search, data structures, dp, graphs, greedy, shortest paths, sortings

Music Festival

binary search, data structures, dp, greedy, sortings

Buying gifts

data structures, greedy, sortings

The Very Beautiful Blanket

bitmasks, constructive algorithms

Symmetree

dfs and similar, hashing, implementation, trees

Dasha and Nightmares

bitmasks, hashing, meet-in-the-middle, strings

Unforgivable Curse (hard version)

brute force, constructive algorithms, dfs and similar, dsu, graphs, greedy, strings

Unforgivable Curse (easy version)

brute force, constructive algorithms, dsu, graphs, greedy, strings

Remove Two Letters

data structures, greedy, hashing, strings

Powering the Hero (hard version)

data structures, greedy

Powering the Hero (easy version)

data structures, greedy

Count the Number of Pairs

greedy, strings

Is It a Cat?

implementation, strings

Tree Cutting

bitmasks, dfs and similar, dp

Count Voting

combinatorics, dp, math

Halve or Subtract

binary search, brute force, dp, greedy, sortings