Prepare superposition of basis states with the same parity

*special problem

Prepare superposition of basis states with 0s

*special problem

"Is the number divisible by 3?" oracle

*special problem

"Is the bit string balanced?" oracle

*special problem

Distinguish Y, XZ, -Y and -XZ

*special problem

Distinguish four Pauli gates

*special problem

Distinguish Rz(θ) from Ry(θ)

*special problem

Distinguish Rz from R1

*special problem

Distinguish H from X

*special problem

Distinguish I, CNOTs and SWAP

*special problem

Figure out direction of CNOT

*special problem

Quantum Classification - 2

*special problem

Quantum Classification - 1

*special problem

Prepare state |01⟩ + |10⟩ + |11⟩

*special problem

Decrement

*special problem

Increment

*special problem

Distinguish Z from -Z

*special problem

Distinguish I ⊗ X from CNOT

*special problem

Distinguish Z from S

*special problem

Distinguish I from Z

*special problem

Distinguish I from X

*special problem

Guess Divisors Count

constructive algorithms, interactive, number theory

Restorer Distance

binary search, greedy, math, sortings, ternary search

Game With Array

constructive algorithms, math

Count Triangles

binary search, implementation, math, two pointers

Young Explorers

dp, greedy, sortings

Sequence with Digits

brute force, implementation, math

Find a Gift

binary search, interactive, probabilities

Summoning Minions

constructive algorithms, dp, flows, graph matchings, greedy, sortings

Graph Coloring

dfs and similar, dp, graphs

Multiset

binary search, data structures

Not So Simple Polygon Embedding

binary search, brute force, geometry, math

Simple Polygon Embedding

binary search, geometry, math, ternary search

Ternary String

binary search, dp, implementation, two pointers

Alarm Clock

math

Decreasing Heights

brute force, dp

K-periodic Garland

brute force, dp, greedy

Constructing the Array

constructive algorithms, data structures, sortings

Board Moves

math

Two Arrays And Swaps

greedy, sortings

Most Unstable Array

constructive algorithms, greedy, math

Special Permutation

constructive algorithms

Binary String Reconstruction

constructive algorithms, dfs and similar, math

Special Elements

brute force, implementation, two pointers

Alice, Bob and Candies

implementation

K-th Not Divisible by n

binary search, math

Same Parity Summands

constructive algorithms, math

Sum of Round Numbers

implementation, math

Skier

data structures, implementation

Square?

brute force, implementation, math

A+B (Trial Problem)

implementation

Orac and Models

dp, math, number theory

Orac and Factors

math

Slime and Sequences (Hard Version)

dp, fft, math

Slime and Sequences (Easy Version)

dp, fft, math

Slime and Hats

constructive algorithms, dp, greedy

Slime and Biscuits

math, probabilities

Orac and Game of Life

dfs and similar, graphs, implementation, shortest paths

Orac and Medians

constructive algorithms, greedy, math

Orac and LCM

data structures, math, number theory

Phoenix and Memory

data structures, dfs and similar, graphs, greedy

Phoenix and Berries

brute force, dp, greedy, math

Phoenix and Science

binary search, constructive algorithms, greedy, implementation, math

Phoenix and Distribution

constructive algorithms, greedy, sortings, strings

Phoenix and Beauty

constructive algorithms, data structures, greedy, sortings

Phoenix and Balance

greedy, math

Pac-Man 2.0

*special problem, dp

Game with Segments

*special problem, data structures, games

Two IP Cameras

*special problem, math, number theory

Dune II: Battle For Arrakis

*special problem, data structures, greedy, math

Magic Tricks

*special problem, dp, graphs

Constructing the Dungeon

*special problem, graphs, greedy

Spring Cleaning

*special problem, greedy, sortings

Boot Camp

*special problem, greedy

Color Revolution

*special problem, math

Card Constructions

binary search, brute force, dp, math

Puzzle Pieces

math

Piet's Palette

matrices

Train Tracks

data structures, trees

Résumé Review

binary search, greedy, math

Quantifier Question

dfs and similar, dp, graphs, math

Monopole Magnets

constructive algorithms, dfs and similar, dsu, graphs

Hilbert's Hotel

math, number theory, sortings

Restore the Permutation by Sorted Segments

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

Weights Distributing

brute force, graphs, greedy, shortest paths, sortings

Constant Palindrome Sum

brute force, data structures, greedy, two pointers

Alternating Subsequence

dp, greedy, two pointers

Balanced Array

constructive algorithms, math

Candies

brute force, math

Make It Ascending

bitmasks, brute force, dp

Placing Rooks

combinatorics, fft, math

Multiple Testcases

binary search, constructive algorithms, data structures, greedy, sortings, two pointers

Yet Another Counting Problem

math, number theory

Binary Period

constructive algorithms, strings

Road To Zero

greedy, math

Nastya and Door

greedy, implementation

Nastya and Rice

math

Nastya and CBS

brute force, data structures, hashing

Nastya and Time Machine

constructive algorithms, dfs and similar, graphs, trees

Nastya and Unexpected Guest

dfs and similar, dp, graphs, shortest paths