Write an algorithm in pseudocode and declare the input and output parameters, to solve the following task(ASAP).

There's N piece of a possibly incomplete puzzle. Each puzzle has 4 sides , given the serial number of the side pattern. Two pieces of puzzle can only be joined together if they have sides with the same pattern. Those on the edge have one or two 0-line (="straight") sides.

It can be assumed that the fit was clear for the entire puzzle, i.e. any (not 0 pattern) side of any puzzle piece had exactly one matching piece.

Let's list the puzzle pieces for which you can't find any of their neighbors.

Your kind help is very much appreciated ASAP.