Exercise 12, Task 3

The function starts in the final point and calculates the minimum distances of the cells until it reaches the start point.

function matr = makewave(startcell,finalcell)

global map;

distmap = zeros(size(map,1),size(map,2));

distmap(finalcell(1),finalcell(2))=2;

queue = finalcell;

reached = 0;

while(size(queue,1) && reached==0)

    [crt,queue] = retrieve(queue);

    n = neighbours(crt);

    for i=1:size(n,1)

        if(map(n(i,1),n(i,2))==0)

           d = distmap(crt(1),crt(2)) + celldist(crt,n(i,:));

           if(distmap(n(i,1),n(i,2))==0) 

                distmap(n(i,1),n(i,2))= d;

                queue = insert(n(i,:),queue);

           elseif(distmap(n(i,1),n(i,2)) > d) 

                distmap(n(i,1),n(i,2)) = d;

           end

        end

        if(n(i,:)==startcell)

            reached = 1;

        end    

    end

end    

if(reached==0)

    fprintf('The wave did not reach the starting point.')

end

matr = distmap;

end