Ideas:
- Matrix multiplication and it's applications like finding shortest path in graphs
- Solving of systems of equations
- Cryptography -- many cryptoprotocols represent data or keys or theirs internal structures in a form of matrices.
- Any algo on graphs represented as matrices
I must have been having some kind of fixation on matrices, sorry :)
For 4D arrays one obvious thing I can think of is the representation of 3D environment changing in time, so 4th dimension represents time scale. Or any representation of 3D which have additional associated property placed in 4th dimension of array.
