Hashing
Problems on hashing, including comparing substrings with polynomial hashes, finding repeated and palindromic substrings, counting distinct elements, hash tables, and comparing sets, arrays and trees in constant time.
The set and map article in the Data structures section covers hash-based containers. Related problem sets are under Strings and String suffix structures.
Problems
Poem Titles#210
Hard
CheckSum#270
Easy
Jammed#412
Easy
2D-Nim#1009
Medium
Tiger's Lucky Number#1054
Very easy
Dad is strong...#1430
Very easy
Fibonacci sequence#2019
Medium
Words#2200
Easy
User Names#2757
Medium
Queens High#2873
Hard
Join#3183
Medium
New Year#3217
Very easy
Captain Q`s Treasure#3435
Very hard
Label#3514
Hard
Pizza Hawaii#3777
Very easy
3D Blobs#3824
Medium
Pattern matching#4172
Very hard
Equal substrings#4843
Very easy
Hexerpents of Hexwamp#4871
Very hard
Very simple#4898
Very easy