c语言打印二叉树树形结构（转载自：http://blog.csdn.net/xzongyuan）

#include
#include
#include
#define NUM 5
typedef struct _node
{
   int value;
   struct _node *left;
   struct _node *right;
}TNode,*Tree;

//add a *next in q_node is my purpose
//other wise , we need to add in the Tree node struct
//So, for the sake of doesn't modify the struct of tree
//I design a q_node struct to include it
//we can use define command to make it as a template.
typedef struct _q_node
{
  TNode *t_node;
  int depth;
  int blank;  //0: means correspoinding tree node is not NULL(default)
  struct _q_node *next;
}QNode;

typedef struct _Queue
{
   QNode *head;
   QNode *tail;
}Queue;

Queue* init_queue()
{
   Queue *queue=(Queue*)malloc(sizeof(Queue));
   queue->head = queue->tail = NULL;
   return queue;
}

int enQueue(Queue *pQueue,TNode *pTNode,int pDepth)
{

      QNode *pQNode = (QNode *)malloc(sizeof(QNode));
      pQNode->depth = pDepth;
      pQNode->blank = 0; //default config 
      if(pTNode==NULL)
      {
         //change default setting; 1 means it's blank QNode
         pQNode->blank =1;
      }

      pQNode->t_node= pTNode;
      if(pQueue->head == NULL)
      {//when it's empty
           pQueue->head = pQNode;
           pQueue->tail = pQNode;
      }
      else
      {
           pQueue->tail->next = pQNode;
           pQueue->tail = pQNode;
      }
}

QNode* deQueue(Queue *pQueue)
{
        if(pQueue->head == NULL)
        {
           return NULL;
        }

        QNode *deNode= pQueue->head;
        pQueue->head = pQueue->head->next;
        return deNode;
}

TNode* init_TNode(int value)
{
    TNode  *new_node = (TNode*)malloc(sizeof(TNode));
    new_node->value=value;
    new_node->left = new_node->right = NULL;
    return new_node;
}

//0:empty
int ifEmpty(Queue *pQueue)
{
   if(pQueue->head == NULL)
   {
     //printf("empty tree\n");
     return 0;
   }

   //printf("queue is not empty\n");
   return 1;
}


int insert_tree(Tree pTree,int pValue)
{

   //found NULL sub tree, then add to his father->left
   if(!pTree)
   {
      return 0;
   }
   TNode *tNode = init_TNode(pValue);
   if(tNode==NULL)
   {
       printf("create TNode error!\n");
       return 0;
   }


   if(pValue < pTree->value)
        if(insert_tree(pTree->left,pValue)==0)
        {
           //no left child any more,set a new left child to pTree
           pTree->left = tNode;
           printf("insert :%d\n",pValue);
        }
   if(pValue > pTree->value)
        if(insert_tree(pTree->right,pValue)==0)
        {
           pTree->right = tNode;
           printf("insert :%d\n",pValue);
        }
}

Tree creatTree(int num)
{
    srand(time(NULL));
    Tree root = init_TNode(rand()%100);
    printf("root is %d\n",root->value);
    int i ;
    for(i=1;ileft);
  rh = get_tree_height(pRoot->right);
  return (lhdepth+1;

     if(qNode->depth > current_depth)
     {
         current_depth = qNode->depth;
         printf("%s\n",buf_branch);
         sprintf(buf_branch,"\n");  //reset the buffer after print
     }
// ***************0****************  pad_between = 31 ; pad_front = 15  (depth == 1)
// *******0***************0********  pad_between = 15 ; pad_front = 7   (depth == 2)
// ***0*******0*******0*******0****  pad_between = 7  ; pad_front = 3   (depth == 3)
// *0***0***0***0***0***0***0***0**  pad_between = 3  ; pad_front = 1   (depth == 4)
// 0*0*0*0*0*0*0*0*0*0*0*0*0*0*0*0*  pad_between = 1  ; pad_front = 0;  (depth == 5)
// Tree height = 5
// pad_num = 1
// padding between node = (1+2*pad_front)*pad_num = (1+ (1<<(height-depth))-1)*pad_num

     int pad_front = (1<< (height - current_depth))-1;
     int pad_blank = (pad_front-1)>>1;
     int pad_under = (pad_front+1)>>1;

       //add the parent node's padding:2
        if(pad_front == 0)    printf("%.*s%*s",pad_num,leaf,pad_num," ");

        else
            {
             printf("%*s%.*s%*s",pad_front*pad_num," ",pad_num,leaf,(1+pad_front)*pad_num," ");
             char *new_buf=(char*)malloc(100);
             char *old_buf = buf_branch;

             sprintf(buf_branch,"%s%s",old_buf,new_buf);
            }
       if(child_depth<=height)
       {
         //enter two NULL sub-tree node.
         //every time you enter NULL TNode,there's corresponding blank QNode.
         enQueue(pQueue,NULL,child_depth);
         enQueue(pQueue,NULL,child_depth);
       }
     }
     else
     {
        if(pad_front == 0)
            {
              printf("%*d%*s",pad_num,qNode->t_node->value,pad_num," ");
            }
        else
            {

               char *new_buf=(char*)malloc(100);
               char *old_buf=buf_branch;
               printf("%*s%*d%*s",pad_front*pad_num," ",pad_num,qNode->t_node->value,(1+pad_front)*pad_num," ");
               sprintf(buf_branch,"%s%s",old_buf,new_buf);
            }
       if(child_depth <=height)
       {
         enQueue(pQueue,qNode->t_node->left,child_depth);
         enQueue(pQueue,qNode->t_node->right,child_depth);
       }
     }

   } //while end   
     printf("\n-----------\nbreath end!\n-----------\n");

   return 1;
}

int main(int argc,char **argv)
{
  Queue *queue=init_queue();
  int i;

  ifEmpty(queue);
  printf("insert node to queue\n");

  int num = NUM; //default
  if(argc == 2)
  {
    num = atoi(argv[1]);
  }

  Tree root = creatTree(num);
  if(!root)
  {
    printf("create Tree failed!\n");
    return 0;
  }

  breath_travel(root,queue);
  return 0;
}