StackOverflowError -java

Question

I am writing a code to run DFS on a graph however these graphs are huge. I am getting a stack overflow error on DFS visit however other people were able to run DFS visit without any problems. Is there any reason why I would be getting a StackOverFlow error? I tried allocating more memory (I have 16gb RAM) however it caps me at 1gb ram.

public void DFSVisit(Graph <String, String> graph, String current, int [] data, StackObject [] finish, boolean complicated){
    //data stores the time
    data[9]++;
    graph.setAnnotation(current, "time", data[9]);
    graph.setAnnotation(current, "color", "gray");
    Iterator <ArrayList<String>> itr = graph.outAdjacentVertices(current);
    ArrayList <String> currentlist = null;
    String adjacent;
    while(itr.hasNext()){
        currentlist = itr.next();
        adjacent = currentlist.get(1);
            if(graph.getAnnotation(adjacent, "color").equals("white")){
                graph.setAnnotation(adjacent, "parent", current);
                DFSVisit(graph, adjacent, data, finish, complicated);
            }
    }
    graph.setAnnotation(current, "color", "black");
    data[9]++;
    graph.setAnnotation(current, "done", data[9]);
    finish[0].done.push(current);
    //System.out.println(current);
}

If the search space is infinite every system running your code will get this exception. — Mohsen Kamrani, Apr 17 '14 at 04:21
You have to mark the current node as visited so you do not come back to it from the adjacent list of vertices. Imagine a simple graph with two vertices and an edge joining them. Both vertices adjacent list will contain each other and your algorithm will just visit them over and over. — anonymous, Apr 17 '14 at 04:26

score 1 · Answer 1 · answered Apr 17 '14 at 04:25

1

Allocating memory will not help. You call DFSVisit inside same method and no return condition defined for the method hence it will throw stackoverflow error.

answered Apr 17 '14 at 04:25

Chamawarna

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4

score 1 · Answer 2 · answered Apr 17 '14 at 04:28

1

You have to stop recursive calls on some point..with some condition..otherwise it will be endless calls and will throw stack-overflow error.

answered Apr 17 '14 at 04:28

niiraj874u

2,180
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score 0 · Answer 3 · edited May 23 '17 at 12:23

0

please note that the space complexity of the DFS is O(b.m) where m is depth of the search space and b is the maximum branching factor, so if m is infinite, you may never be able to solve the problem with an inappropriate implementation.

To find a better example, look at this question on SO.

edited May 23 '17 at 12:23

Community

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answered Apr 17 '14 at 04:25

Mohsen Kamrani

7,177
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score 0 · Accepted Answer · answered Apr 18 '14 at 04:55

0

I switched over to working on my laptop and it worked immediately. Apparently the problem was me using a 32 bit Eclipse instead of a 64 bit Eclipse. I didn't even realize I was using a 32 bit on my desktop.

answered Apr 18 '14 at 04:55

Mocking

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StackOverflowError -java

4 Answers4