Return function in a recursive function code

I think in the first condition you meant K=P. The only reason it can be happening is C never becomes equal to P.

The line

    Function(A,P,K)

does not change C, so there is no point running the call.

If you want to return P from the last termination call to recursive function than you will need to assign it to the output of Function in else condition like this

[C]=Function(A,P,K)
%A is adjacency matrix of a Graph say
%P, K are vectors
if (terminating condition)
   C=P;
   return
else 
    ......
    P=.....%redefined
    K=.....%redefined
    C = Function(A,P,K);
end
end

No point of using disp if you want the output in a matrix.