Random Ranking

dp, math, probabilities

Yaroslav and Arrangements

dp

Mystic Carvings

data structures

Greedy Petya

*special problem, dfs and similar, graphs, greedy

Polo the Penguin and Lucky Numbers

dp, implementation, math

Ladies' Shop

constructive algorithms, fft, math

Cow Tennis Tournament

combinatorics, data structures, math

Sequence Transformation

brute force, data structures, dp, implementation, math

k-Maximum Subsequence Sum

data structures, flows, graphs, implementation

Google Code Jam

dp, probabilities

Mirror Room

data structures, implementation

Roadside Trees

data structures, dp

Maxim and Calculator

brute force, dp, two pointers

Tree and Table

dfs and similar, dp, implementation, trees

Matrix

data structures

Numbers

Road Repairs

dfs and similar, graphs, greedy

Tape Programming

data structures, implementation

Graph Game

graphs

Quick Tortoise

bitmasks, divide and conquer, dp

Fence

binary search, data structures, string suffix structures

Noble Knight's Path

data structures, trees

Planar Graph

flows, geometry, graphs

Spider

geometry, graphs

Alien DNA

data structures, dsu, trees

Bitonix' Patrol

bitmasks, brute force, combinatorics, dfs and similar, math

Privatization

flows, graphs

Little Elephant and Strings

data structures, implementation, string suffix structures, two pointers

The Next Good String

data structures, greedy, hashing, strings

Fibonacci Number

brute force, math, matrices

Two Segments

data structures

Heaven Tour

data structures, greedy

BRT Contract

data structures

Soap Time! - 2

binary search, data structures

Candy Shop

greedy

Gnomes of Might and Magic

data structures, graphs, implementation, shortest paths

Wizards and Bets

dfs and similar, graphs, math, matrices

Wizards and Roads

data structures, divide and conquer, graph matchings, graphs, greedy

e-Government

data structures, dfs and similar, dp, strings, trees

Large Refrigerator

brute force

Mrs. Hudson's Pancakes

brute force, dp

Martian Colony

geometry

Freezing with Style

binary search, data structures, divide and conquer, trees

Lucky Pair

combinatorics, data structures, implementation

Help Greg the Dwarf 2

geometry

Hellish Constraints

brute force, dp, two pointers

Weak Subsequence

combinatorics

Birthday

geometry, math

Pills

brute force, flows

Tree or not Tree

data structures, divide and conquer, implementation, trees

Petya and Rectangle

Buying Sets

flows, graph matchings

Fire and Ice

greedy

Two Subsequences

bitmasks, dp

Security System

math

Password

bitmasks, dp, shortest paths

Martian Food

geometry

Shift It!

constructive algorithms

Plane of Tanks

brute force, geometry

Contact

geometry

Harry Potter and Moving Staircases

dfs and similar, implementation

Chess

math, shortest paths

Caterpillar

dfs and similar, dp, graphs, trees

Black and White

constructive algorithms

Snow sellers

greedy, sortings

Tricky and Clever Password

binary search, constructive algorithms, data structures, greedy, hashing, strings

DravDe saves the world

geometry, math

Fairy

dfs and similar, divide and conquer, dsu

Points

data structures

Palisection

strings

Forward, march!

binary search, dp, greedy

LCIS

dp