How to implement depth first search for graph with a non-recursive approach

Question

I have spent lots of time on this issue. However, I can only find solutions with non-recursive methods for a tree: Non recursive for tree, or a recursive method for the grap

Answer 1

okay. if you are still looking for a java code

dfs(Vertex start){
    Stack stack = new Stack<>(); // initialize a stack
    List visited = new ArrayList<>();//maintains order of visited nodes
    stack.push(start); // push the start
    while(!stack.isEmpty()){ //check if stack is empty
        Vertex popped = stack.pop(); // pop the top of the stack
        if(!visited.contains(popped)){ //backtrack if the vertex is already visited
            visited.add(popped); //mark it as visited as it is not yet visited
            for(Vertex adjacent: popped.getAdjacents()){ //get the adjacents of the vertex as add them to the stack
                    stack.add(adjacent);
            }
        }
    }

    for(Vertex v1 : visited){
        System.out.println(v1.getId());
    }
}