C 二叉树的建立，遍历（递归，非递归）

 

#include
#include

#define MAXSIZE 20

typedef struct BiTnode{
 char data;
 struct BiTnode *lchild,*rchild;
}BiTnode,*BiTree;


//浜屽弶鏍戠殑閫掑綊寤虹珛
int i = 0;
BiTree Create(BiTree t,char s[])
{
 char ch;
 ch = s[i++];

 if(ch == ' ')
 {
  t = NULL;
 }
 else
 {
  if(!(t = (BiTree)malloc(sizeof(BiTnode))))
  {
   printf("fail to malloc!\n");
   exit(0);
  }
  else
  {
   t->data = ch;
   t->lchild = Create(t->lchild,s);
   t->rchild = Create(t->rchild,s);
  }
 }
 return t;
}



//涓簭閬嶅巻
/*
void display(BiTree t)
{
 BiTree stack[MAXSIZE],p;
 int top = -1;
 if(t)
 {
  p = t;
  while(top > -1 || p)
  {
   while(p)
   {
    stack[++top] = p;
    p = p->lchild;
   }
   if(top > -1)
   {
    p = stack[top--];
    printf("%c ",p->data);
    p = p->rchild;
   }
  }
  printf("\n");
 }
}
/*/



//鍓嶅簭閬嶅巻
/*
void display(BiTree t)
{
 BiTree stack[MAXSIZE],p;
 int top = -1;
 if(t)
 {
  p = t;
  while(top > -1 || p)
  {
   while(p)
   {
    printf("%c ",p->data);
    stack[++top] = p;
    p = p->lchild;
   }
   if(top > -1)
   {
    p = stack[top--];
    p = p->rchild;

   }
  }
  printf("\n");
 }
}

*//*



//鍓嶅簭閬嶅巻
void display(BiTree t)
{
     BiTree stack[MAXSIZE], p;
     int top = -1;
     if (t)
     {
         stack[++top] = t;
         while (top > -1)
         {
             p = stack[top--];
             printf("%c ", p->data);
             if (p->rchild)
              {
                  stack[++top] = p->rchild;
              }
             if (p->lchild)
              {
                  stack[++top] = p->lchild;
              }
         }
         printf("\n");
     }
}*/

/*

//闈為€掑綊鍚庡簭閬嶅巻

void display(BiTree t)
{
 BiTree m,stack[MAXSIZE];
 int top = -1;
 int flag;

 if(t)
 {
loop:
  flag = 1;
  m = NULL;
  while(t)
  {
   stack[++top] = t;
   t = t->lchild;
  }
  while(flag)
  {
   t = stack[top];
   if(t->rchild == m)
   {
    printf("%c ",t->data);
    top--;
    m = t;
   }
   else
   {
    flag = 0;
    t = t->rchild;
   }
  }
  if(top>-1)
   goto loop;
 }

 printf("\n");
}

*/



//闈為€掑綊鍚庡簭閬嶅巻
void display(BiTree t)
{
    BiTree p = t, stack[MAXSIZE];
    int tag[MAXSIZE];
    int top = -1;

 do
     {
         while(p != NULL)
         {
             stack[++top] = p;
             tag[top] = 0;
             p = p->lchild;
         }
         if(top > -1)
         {
             if(!tag[top])
              {
                  p = stack[top];
                  p = p->rchild;
                  tag[top] = 1;
              }
             else
              {
                   printf("%c ", stack[top--]->data);
              }
         }
     }while((p != NULL)||(top > -1));
 printf("\n");
}


//閫掑綊鍓嶅簭閬嶅巻
/*void display(BiTree t)
{
 if(t)
 {
  printf("%c ",t->data);
  display(t->lchild);
  display(t->rchild)锛?
 }
}*/

//閫掑綊涓簭閬嶅巻
/*void display(BiTree t)
{
 if(t)
 {
  display(t->lchild);
  printf("%c ",t->data);
  display(t->rchild)锛?
 }
}*/

 //閫掑綊鍚庡簭閬嶅巻
/*void display(BiTree t)
{
 if(t)
 {

  display(t->lchild);
  display(t->rchild);
  printf("%c ",t->data);
 }
}*/

int main(int argc,char *argv[])
{
 BiTree t;
 char s[] = "abc  de f  g    ";
 t = Create(t,s);
 display(t);

 return 0;
}