Maximise Sum

binary search, data structures

Appending Permutations (Hard Version)

combinatorics, dp

Appending Permutations (Easy Version)

combinatorics, dp

Make it Zero

constructive algorithms, greedy, math

Make a Palindrome

greedy, sortings, two pointers

Modular Sorting

brute force, data structures, greedy, math, number theory, sortings

Minimize Fixed Points

constructive algorithms, number theory

MEX Count

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

Tree Parking

combinatorics, fft, math, trees

Colorful Polygon

constructive algorithms, divide and conquer, geometry

Greedy Grid Counting

combinatorics, dp, greedy, math

Traffic Lights

brute force, data structures, divide and conquer, dp, graphs, greedy, shortest paths

Manhattan Pairs

constructive algorithms, geometry, greedy, math, sortings

Ice Baby

binary search, brute force, data structures, dp, implementation, sortings

Gangsta

data structures, divide and conquer, math, sortings

Yamakasi

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

Sponsor of Your Problems

dp, greedy, implementation, strings

Eulerian Line Graph

graphs, greedy, math

Superb Graphs

2-sat, graphs

Lanes of Cars

binary search, dp, ternary search

Matrix game

combinatorics, math

Divine Tree

constructive algorithms, greedy, math, sortings, trees

Volcanic Eruptions

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

And Constraint

bitmasks, dp, greedy

Token Removing

combinatorics, dp, math

Shifts and Swaps

data structures, graphs, hashing, trees

Grid Coloring

constructive algorithms, geometry, greedy, math

Red Light, Green Light (Hard version)

binary search, brute force, data structures, dfs and similar, dp, graphs, implementation, math, number theory

Red Light, Green Light (Easy version)

brute force, dfs and similar, dp, graphs, implementation, number theory

Incessant Rain

data structures, divide and conquer, sortings

Omg Graph

brute force, dsu, graphs, greedy, shortest paths, sortings

Wildflower

combinatorics, dfs and similar, trees

Lost Soul

brute force, greedy

Gellyfish and Lycoris Radiata (Hard Version)

data structures

Gellyfish and Lycoris Radiata (Easy Version)

data structures

Gellyfish and Mayflower

dp, graphs

Gellyfish and Forget-Me-Not

bitmasks, dp, games, greedy, math

Gellyfish and Eternal Violet

combinatorics, dp, greedy, math, probabilities

Gellyfish and Camellia Japonica

brute force, constructive algorithms, dfs and similar, dp, graphs, greedy, trees

Gellyfish and Flaming Peony

constructive algorithms, dp, math, number theory

Build an Array

brute force, constructive algorithms, dp, greedy, math, number theory

Small Operations

binary search, brute force, dfs and similar, dp, math, number theory, sortings

Kirei Attacks the Estate

dfs and similar, dp, greedy, trees

Come a Little Closer

brute force, greedy, implementation, math

Two Arrays

constructive algorithms, dfs and similar, graphs, math

From Kazan with Love

dfs and similar, graphs, implementation, trees

Cheater

binary search, constructive algorithms, greedy, implementation

Smilo and Minecraft

brute force, constructive algorithms, greedy

Variables and Operations

graphs, greedy, shortest paths

Tree Colorings

combinatorics, dfs and similar, dp, graphs, math, number theory, trees

Reachability and Tree

constructive algorithms, dfs and similar, graphs, trees

Divisible Subarrays

binary search, bitmasks, brute force, data structures, interactive

Puzzle

brute force, constructive algorithms, greedy, math

Changing the String

binary search, data structures, greedy, implementation, sortings, strings

Creating a Schedule

constructive algorithms, data structures, greedy, implementation, sortings

Faculty

brute force, greedy, math, number theory

Melody

dfs and similar, graphs, implementation

Fewer Batteries

binary search, dfs and similar, dp, graphs, greedy, hashing

Racing

constructive algorithms, greedy

Penguin Steps

binary search, dfs and similar, flows, graphs, shortest paths

Binary String Wowee

combinatorics, dp, strings

D/D/D

dfs and similar, graphs, greedy, shortest paths

Hacking Numbers (Hard Version)

constructive algorithms, interactive, math, number theory

Hacking Numbers (Medium Version)

constructive algorithms, interactive, math, number theory

Hacking Numbers (Easy Version)

bitmasks, constructive algorithms, interactive, math, number theory

Fallen Towers

binary search, greedy

Spruce Dispute

constructive algorithms, dfs and similar, graphs, greedy, implementation, shortest paths, trees

Needle in a Numstack

binary search, brute force, implementation, interactive

Neo's Escape

binary search, brute force, data structures, dp, dsu, graphs, greedy, implementation

Cycling (Hard Version)

binary search, brute force, data structures, dp, greedy

Cycling (Easy Version)

binary search, brute force, dp, greedy

Ain and Apple Tree

binary search, constructive algorithms, greedy, math, trees

Apple Tree Traversing

brute force, dfs and similar, greedy, implementation, trees

Maximum Subarray Sum

binary search, constructive algorithms, dp, implementation, math

Baudelaire (hard version)

binary search, dfs and similar, divide and conquer, implementation, interactive, trees

Baudelaire (easy version)

binary search, constructive algorithms, divide and conquer, greedy, interactive, trees

Goblin

dfs and similar, dp, dsu, greedy, math

Wolf

binary search, greedy, math

Flower Boy

binary search, dp, greedy, two pointers

Modulo 3

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

Numbers and Strings

binary search, brute force, dfs and similar, dp, implementation, math

Unpleasant Strings

binary search, dp, greedy, strings

Array and GCD

binary search, greedy, math, number theory

Maximize Nor

bitmasks, data structures, dp, implementation, sortings

Keep the Sum

constructive algorithms, implementation, two pointers

Local Construction

constructive algorithms, dfs and similar, implementation, two pointers

Median Splits

binary search, greedy, implementation, sortings

Shoo Shatters the Sunshine

combinatorics, dp, trees

Kia Bakes a Cake

data structures, dp, greedy, trees

Mani and Segments

data structures, implementation, sortings, two pointers

23 Kingdom

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

Quartet Swapping

brute force, data structures, divide and conquer, greedy, sortings

Sasha and the Apartment Purchase

math, sortings

Lost Luggage

dp, flows

Clearing the Snowdrift

data structures, dfs and similar, dp, greedy

Homework

bitmasks, math, matrices

Bermuda Triangle

chinese remainder theorem, geometry, implementation, math, number theory

Baggage Claim

combinatorics, dfs and similar, dp, dsu, graphs, implementation, math, trees

Sports Betting

2-sat, brute force, math, sortings

Wonderful XOR Problem

bitmasks, combinatorics, dp, fft, math