Question

I’m writing breadth first, depth first, and depth first recursive traversal for the following graph:

From what I understand, the traversal should be 0 1 3 6 4 5 2…but i’m only getting that for the depth first traversal, and for the dfs(recursive) and BFS, I’m getting 0 1 3 6 2 4 5. I don’t know which one is right and what I need to do to fix the problem.

Class

    public void depthFirst(int vFirst,int n, int[] isvisited)
   {       //vFirst = 0, n = 6
  int v,i;
  // st is a stack
  st.push(vFirst);

  while(!st.isEmpty())
  {
      v = st.pop();
      if(isvisited[v]==0)
      {
          System.out.print(v);
          isvisited[v]=1;
      }
      for ( i = 0; i <= n; i++)
      {
          if((adjMatrix[v][i] == 1) && (isvisited[i] == 0))
          {
              st.push(v);
              isvisited[i]=1;
              System.out.print(" " + i);
              v = i;
          }
      }
  }

}

public void depthFirstRecursive(int w) {
    int j;     //w = 0;

    visited[w] = 1;
    if (w == 0) {
        System.out.print(w + " ");
    }

    for (j = 0; j <= 6; j++) {
        if ((adjMatrix[w][j] == 1) && (visited[j] == 0)) {
            System.out.print(j + " ");

            depthFirstRecursive(j);
        } 

    } 
}

public void breadthFirst(int first, int p) {
    int e;     // first = 0; p = 6
    int[] nodeVisited = new int[7];
    que.add(first);


   while (!que.isEmpty()) {
       e = que.remove();
       if(nodeVisited[e]==0)
          {
              System.out.print(e);
              nodeVisited[e]=1;
          }
       for (int i = 0; i <= p; i++)
          { 

              if((adjMatrix[e][i] == 1) && (nodeVisited[i] == 0))
              {
                  que.add(e);
                  nodeVisited[i]=1;
                  System.out.print(" " + i);
                  e = i;
              } 
          }

   }



}


public static void main(String[] args) {



                        // 1  2  3  4  5  6  7
    int[][] adjMatrix = { {0, 1, 1, 0, 0, 0, 0},
                          {1, 0, 0, 1, 1, 1, 0},
                          {1, 0, 0, 0, 0, 0, 1},
                          {0, 1, 0, 0, 0, 0, 1},
                          {0, 1, 0, 0, 0, 0, 1},
                          {0, 1, 0, 0, 0, 0 ,0},
                          {0, 0, 1, 1, 1, 0, 0}  };


        new myGraphs(adjMatrix);
 }

Answer 1

About following snippet in BFS:

que.add(e);
nodeVisited[i]=1;
System.out.print(" " + i);
e = i;

They why do you change e and add e to queue? It seems incorrect to me.