Problems
Flood-It#6404
Very easy · Greedy algorithms
Chemicals Monitoring#6405
Very hard · Priority Queue · Greedy algorithms
Area Coverage#6406
Easy · Implementation
Bad Signal#6407
Very easy · Greedy algorithms
Cracking the Safe#6408
Medium · Brute force · Math · Depth-first Search
Dreaded Alternating Game#6409
Very easy · Graphs
Encryption#6410
Very easy · Implementation
Fare Dodging#6411
Very easy · Shortest paths · Graphs
Genuine Messages#6412
Very easy · Implementation
How Much?#6413
Very easy · Implementation
Identification Codes#6414
Very easy · Number theory · Math
Just Enough Space#6415
Very easy · Dynamic programming
Keys#6416
Easy · Graphs · Implementation
Administrative Difficulties#6417
Easy · Implementation
Bribe#6418
Medium · Dynamic programming
Cracking the Code#6419
Hard · Strings
Destination Unknown#6420
Very easy · Shortest paths · Graphs
Encoded Coordinates#6421
Hard · Matrix · Dynamic programming
Flying Safely#6422
Easy · Graphs · Trees
Getting Through#6423
Medium · Graphs · Geometry
Hidden Camera#6424
Hard · Geometry
Incognito#6425
Easy · Combinatorics · Sorting
Jailbreak#6426
Very easy · Graphs · Implementation
Beehives#6427
Very easy · Graphs
Bits Equalizer#6428
Medium · Greedy algorithms