Two Strings Swaps

implementation

Three Parts of the Array

binary search, data structures, two pointers

Polycarp's Practice

greedy, implementation, sortings

Adjacent Replacements

implementation

Berland and the Shortest Paths

brute force, dfs and similar, graphs, shortest paths

Median on Segments (General Case Edition)

sortings

Median on Segments (Permutations Edition)

sortings

Polycarp and Div 3

dp, greedy, number theory

Summarize to the Power of Two

brute force, greedy, implementation

Delete from the Left

brute force, implementation, strings

Tanya and Stairways

implementation

Sonya and Bitwise OR

bitmasks, data structures, divide and conquer

Sonya and Ice Cream

binary search, data structures, dp, greedy, shortest paths, trees

Sonya and Matrix

brute force, constructive algorithms, implementation

Sonya and Robots

constructive algorithms, implementation

Sonya and Exhibition

constructive algorithms, greedy, implementation, math

Sonya and Hotels

implementation

Abbreviation

dp, hashing, strings

Tree Constructing

constructive algorithms, graphs

Coins and Queries

greedy

Intense Heat

brute force, implementation, math

Binary String Constructing

constructive algorithms

Polycarp's Pockets

implementation

Another array reconstruction algorithm

Bernstein-Vazirani algorithm

Oracle for majority function

Oracle for f(x) = b * x + (1 - b) * (1 - x) mod 2

Oracle for f(x) = b * x mod 2

Distinguish zero state and plus state without errors

Distinguish zero state and plus state with minimum error

Distinguish four 2-qubit states - 2

Distinguish four 2-qubit states

Distinguish GHZ state and W state

Distinguish zero state and W state

Generate W state

Generate superposition of two basis states

Generate superposition of zero state and a basis state

Generate superposition of all basis states

Deutsch-Jozsa algorithm

*special problem

Oracle for f(x) = parity of the number of 1s in x

*special problem

Oracle for f(x) = k-th element of x

*special problem

Distinguish multi-qubit basis states

*special problem

Distinguish Bell states

*special problem

Distinguish plus state and minus state

*special problem

Generate GHZ state

*special problem

Generate Bell state

*special problem

Generate plus state or minus state

*special problem

Two-Paths

data structures, dp, trees

One Occurrence

data structures, divide and conquer

We Need More Bosses

dfs and similar, graphs, trees

Yet Another Problem On a Subsequence

combinatorics, dp

Covered Points Count

data structures, implementation, sortings

Light It Up

greedy

Codehorses T-shirts

greedy, implementation

Cards and Joy

dp

Reachability from the Capital

dfs and similar, graphs, greedy

Equalize the Remainders

data structures, greedy, implementation

Alphabetic Removals

implementation

Reversing Encryption

implementation

Mishka and Contest

brute force, implementation

Cutting

dp, greedy, sortings

Balloons

constructive algorithms, implementation

Good Subsegments

data structures

Cycles in product

combinatorics, divide and conquer, trees

Sky Full of Stars

combinatorics, math

Roman Digits

brute force, combinatorics, dp, greedy, math

Convert to Ones

brute force, greedy, implementation, math

World Cup

binary search, math

Hit the Lottery

dp, greedy

Cowmpany Cowmpensation

combinatorics, dp, math, trees

Number Clicker

divide and conquer, graphs, meet-in-the-middle, number theory

Game

math

Leaving the Bar

brute force, data structures, geometry, greedy, math, sortings

Suit and Tie

greedy, implementation, math

Tesla

constructive algorithms, implementation

Knights of a Polygonal Table

greedy, implementation, sortings

Fingerprints

implementation

The Moral Dilemma

Nikita and Order Statistics

chinese remainder theorem, fft, math

Compute Power

binary search, dp, greedy

Careful Maneuvering

bitmasks, brute force, geometry

Open Communication

bitmasks, brute force

Two Squares

geometry, implementation

Nastya and King-Shamans

binary search, data structures

Nastya and a Game

brute force, implementation, math

Nastya and a Wardrobe

math

Nastya Studies Informatics

math, number theory

Nastya and an Array

implementation, sortings

Concise and clear

brute force, greedy, implementation, math

Bus Number

brute force, combinatorics, math

Bishwock

dp, greedy

Candies

binary search, implementation

Getting an A

greedy, sortings

If at first you don't succeed...

implementation

GCD Counting

divide and conquer, dp, dsu, number theory, trees

Flow Control

dfs and similar, dp, greedy, trees

Post Lamps

brute force, greedy

Graph And Its Complement

constructive algorithms, graphs, implementation

Bracket Sequences Concatenation Problem

implementation

Micro-World

greedy, sortings