typedef enum{notVisited, visited, noState}State;

typedef struct{
  State state;
}VisitStatus;

typedef struct treeNode{

  struct treeNode *parent;
  void *key;
  void *value;
  List **childList;
  VisitStatus *visitState;
}Node;

typedef struct Tree{ //Multi walk

  Node *root;
  int size;
}Tree;

/*
  Algorithm: Pre-order traversal of n-ary tree:
  0) Assuming node pointer is pointing to root node, which is, not NULL.
  1) Visit node, if not visited
  2) From that node,
     If first sub-tree exists, and
     If root node of that first sub-tree never visted,
     then traverse to root node of first sub-tree.
     Go to step 1 and continue until a node (that has visted root of first sub-tree) or (that has no first sub-tree exists)
  3) From that node,
      Repeat till that node has (nthSubTree =secondSubTree, thirdSubTree, ...., nthSubTree){
        If nthSubTree exists, and
        If root node of nthSubTree not visited,{
          then traverse to root node of nthSubTree
          Go to step 1.
        }
        else{
          continue;
        }
      }// end repeat
  4) We reach this step, because that node has,
     Either sub-trees exist but all sub-trees visited
           or
     No sub trees exist
     Reach parent node and go to step-1 for applying pre-order traversal on that node
*/
static void preOrderTraverse(Node *n, ProcessItem action, List *list, compareTo compare){
 ...
}