Problem 42853. Fifteen Parity Check
The Matlab function fifteen initializes the 4x4 array with randperm(16), which produces 50% unsolvable puzzles. A two stage parity check from wikipedia details the method of distance of the empty cell to index 16 plus the number of swaps to produce a 1:16 sequence must be Even to be a valid puzzle. The 16 is the empty space.
Given a 4x4 matrix determine if it is valid(1) or invalid(0).
1 2 3 4 1 2 3 4 5 6 7 8 5 6 7 8 9 10 11 12 9 10 11 12 13 15 14 16 Invalid(0) 13 14 16 15 Valid(1)
Who can come up with the best fifteen_check to fix the fifteen function?
Solution Stats
Problem Comments
Solution Comments
Show commentsProblem Recent Solvers20
Suggested Problems
-
4515 Solvers
-
Project Euler: Problem 5, Smallest multiple
1330 Solvers
-
Back to basics 9 - Indexed References
439 Solvers
-
Number of 1s in a binary string
8972 Solvers
-
Getting the indices from a vector
9690 Solvers
More from this Author308
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!