Cant remove stackOverflowError in my code of getMazePaths...

Question

Hello, So I am getting stackoverflow error in my code but I cant debug it, I have put termination condition as well yet hard luck.
Link to the code is: https://pastebin.com/VFZ63v7a

Answer 1

getMazePaths(int sr, int sc, int dr, int dc) {
..
if (sr < dr){
hpaths = getMazePaths(sr, sc +1, dr, dc);

this never stops:
1,1, 5,5 if(1<5) do 1, 1+1, 5,5
1,2, 5,5 if(1<5) do 1, 2+1, 5,5
1,3, 5,5 if(1<5) do 1, 3+1, 5,5
1,4, 5,5 if(1<5) do 1, 4+1, 5,5
1,5, 5,5 if(1<5) do 1, 5+1, 5,5

Answer 2

By these statements, you are repeated calling getMazePaths function infinitely..
So it's causing stack flow error...

if (sr < dr){
hpaths = getMazePaths(sr, sc + 1, dr, dc);
}
if(sc < dc){
vpaths = getMazePaths(sr + 1, sc, dr, dc);
}

Where termination condition you put?

Answer 3

if (sr == dr && sc == dc){

            ArrayList<String> bres = new ArrayList<>();

            bres.add("");

            return bres;

        }

This is the terminating condition.

Answer 4

&& will not work because, until if input numbers n, m are same I think, because either you increasing sr or sc, and using && so if it has to stop, n shloud be equal to m.

So use || opearator , like

if (sr == dr || sc == dc){ //use || instead of &&.
ArrayList<String> bres = new ArrayList<>();
bres.add("");
return bres;
}

Answer 5

Thus condition is there bcoz if we reach there to the last index that is ( 2, 2), then only we will terminate and return

What you did would be failing if any of sr or sc becomes equal to sc or dc.
Like 1,2 and you will enter inside if condition.

Answer 6

zemiak yeah gotcha bruh, thanks.. :)