Bitmasks
Problems on bitmasks, including enumerating all subsets of a small set, dynamic programming over subsets, states of lights and switches, assignment and covering problems with up to twenty items, and puzzles where each cell is on or off.
The bitmasks article in the Basics section explains how to store and iterate over subsets. Related problem sets are under Bitwise operations, Brute force and Dynamic programming.
Problems
Cycle shifts#27
Easy
Unhappy Bus#247
Very easy
AntiGray#725
Very easy
Informants#782
Medium
John#789
Very easy
Hyper-drive#1184
Hard
The number of Mersenne numbers#1354
Very easy
Bitwise Equations#1550
Very easy
Reset bits#1647
Easy
Decoding Task#1650
Very easy
Lowest Bit#1753
Easy
Gray Codes#1780
Very easy
U-turn bits#1845
Very easy
Bit Rotation 2#1850
Very easy
Stones#2787
Easy
Bitset#2802
Very easy
Cubes - 3#2807
Very easy