二叉树2：层次遍历方式及先序、中序、后序（递归与非递归）遍历方式

#include<stdio.h>#include<malloc.h>#include<math.h>#define MaxSize 100typedef char ElemType;typedef struct node{ ElemType data; struct node *lchild; struct node *rchild;}BTNode;// Create BinaryTree by Binary-linked-list BTNode *CreatBTNode(char *str){ BTNode *St[MaxSize],*p=NULL,*b; int top=-1,k,j=0; char ch; b=NULL; ch=str[j]; while (ch!='\0') {  switch(ch)  {  case '(':   top++;   St[top]=p;   k=1;   break;  case ')':   top--;   break;  case',':   k=2;   break;  default:   p=(BTNode*)malloc(sizeof(BTNode));   p->data=ch;   p->lchild=p->rchild=NULL;   if(b==NULL)    b=p;   else   {    switch(k)    {    case 1:     St[top]->lchild=p;     break;    case 2:     St[top]->rchild=p;     break;    }   }  }  j++;  ch=str[j]; } return b;}// output Binary Tree by Tree modelvoid DispBTNode(BTNode *b){ BTNode *St[MaxSize],*p; int K[MaxSize]; int i,c,top=-1; int a=-1; int n=3; p=b; do  {  while(p!=NULL)  {   St[++top]=p;   if(p!=b)    ++n;   K[++a]=n;   p=p->rchild;  }  p=St[top--];  c=K[a--];  n=c;  for(i=0;i<=c;i++)   printf("      ");  printf("----%c\n",p->data);  p=p->lchild; } while (top>-1 || p!=NULL);}// traversal based on levelvoid TravLevel(BTNode *b){ BTNode *Qu[MaxSize]; // Circular-queue int front,rear; front=rear=0; if(b!=NULL)  printf("%c",b->data); rear++; Qu[rear]=b; while(rear!=front) {  front=(front+1)%MaxSize;  b=Qu[front];  if(b->lchild!=NULL)  {   printf("%c",b->lchild->data);   rear=(rear+1)%MaxSize;   Qu[rear]=b->lchild;  }  if(b->rchild!=NULL)  {   printf("%c",b->rchild->data);   rear=(rear+1)%MaxSize;   Qu[rear]=b->rchild;  } } printf("\n");} // traversal based on PreOrder  //   :recursive void PreOrder(BTNode *b){ if(b!=NULL) {  printf("%c",b->data);  PreOrder(b->lchild);  PreOrder(b->rchild); }}  // not recursive void PreOrder2(BTNode *b) {  BTNode *St[MaxSize],*p;  int top=-1;  if(b!=NULL)  {   top++;   St[top]=b;   while(top>-1)   {    p=St[top];    top--;    printf("%c",p->data);    if(p->rchild!=NULL)    {     ++top;     St[top]=p->rchild;    }     if(p->lchild!=NULL)     {      ++top;      St[top]=p->lchild;     }   }  }  printf("\n"); }  // In-Order traversal //  :recursive void InOrder(BTNode *b) {  if(b!=NULL)  {   InOrder(b->rchild);   printf("%c",b->data);   InOrder(b->lchild);  } } // not recursive  void InOrder2(BTNode *b) {  BTNode *St[MaxSize],*p;  int top=-1;  if(b!=NULL)  {   p=b;   while(top>-1||p!=NULL)   {    while(p!=NULL)    {     top++;     St[top]=p;     p=p->lchild;    }    if(top>-1)    {     p=St[top];     top--;     printf("%c",p->data);     p=p->rchild;    }   }  }  printf("\n"); } // traversal based on PostOrder // :recursive void PostOrder(BTNode *b) {  if(b!=NULL)  {   PostOrder(b->lchild);   PostOrder(b->rchild);   printf("%c",b->data);  } } // not recursive :used tags void PostOrder1(BTNode *b) {  BTNode *St[MaxSize];  BTNode *p;  int flag,top=-1;  if(b!=NULL)  {   do    {    while(b!=NULL)    {     top++;     St[top]=b;     b=b->lchild;    }    p=NULL;    flag=1;    while(top!=-1 && flag)    {     b=St[top];     if(b->rchild==p)     {      printf("%c",b->data);      top--;      p=b;     }     else // return above to traversal left subtree of b     {      b=b->rchild;      flag=0;     }    }   }while(top!=-1);   printf("\n");  } } // using the struct-stack to accomplish Post-Traversal void PostOrder2(BTNode *b) {  BTNode *p;  struct   {   BTNode *q;   int tag;  }St[MaxSize];  int top=0;  p=b;  do   {   while(p!=NULL)   {    top++;    St[top].q=p;    St[top].tag=0;    p=p->lchild;   }   if(top>0)   {    p=St[top].q;    if(St[top].tag==1)    {     printf("%c",p->data);     top--;     p=NULL;    }    else    {     St[top].tag=1;     p=p->rchild;    }   }  } while (p!=NULL||top!=0); } void main() {  BTNode *b;  b=CreatBTNode("A(B(D,E(H(J,K(L,M(,N))))),C(F,G(,I)))");  printf("Binary Tree:b");  DispBTNode(b);  printf("\n\n");  printf("traversal based on level:");  TravLevel(b);  printf("\n");  printf("traversal based on PreOrder:\n");  printf("recursive algorithm:");  PreOrder(b);  printf("\n");  printf("not recursive algorithm:");  PreOrder2(b);  printf("\n");  printf("traversal based on InOrder:\n");  printf("recursive algorithm:");  InOrder(b);  printf("\n");  printf("not recursive:");  InOrder2(b);  printf("\n");  printf("traversal based on PostOrder:");  printf("recursive algorithm:");  PostOrder(b);  printf("\n");  printf("not recursive algorithm 1:");  PostOrder1(b);  printf("not recursive algorithm 2:");  PostOrder2(b);  printf("\n"); }