二叉树的递归、层次与非递归遍历

来源：互联网发布：vmware player mac 编辑：程序博客网时间：2024/05/22 15:49

#include<stdlib.h>

#define STACKINITSIZE 100      //栈大小#define STACKINCREASESIZE 20   //栈单次扩容量   //节点声明，数据域、左孩子指针、右孩子指针typedef struct node{    char data;    struct node *lchild,*rchild;}BiTNode,*BiTree;  //用于非递归遍历的栈存储的声明，栈底指针、栈顶指针、栈大小typedef struct stack  {      BiTree * base,* top;      int stacksize;  }Sqstack;      /*****************栈的操作定义********************/    //初始化栈  void InitStack( Sqstack &s )  {      s.base = (BiTree *)malloc(STACKINITSIZE*sizeof(BiTree));      if ( !s.base )      {      printf("InitStack内存分配出错\n");exit(0);    }          s.top = s.base;      s.stacksize = STACKINITSIZE;  }    //元素入栈  void Push( Sqstack &s, BiTree e )  {      if ( s.top - s.base >= s.stacksize )      {      s.base = (BiTree *)realloc(s.base,(s.stacksize+STACKINCREASESIZE)*sizeof(BiTree));  //动态内存分配，栈大小不足时，自动申请扩大空间。    if ( !s.base )          {          printf("Push内存分配出错\n");          exit(0);          }             s.top = s.base + s.stacksize;      s.stacksize += STACKINCREASESIZE;      }       *s.top++ = e; //元素入栈 }    //获得栈顶元素  void GetTop( Sqstack s, BiTree &e )  {      e = *(s.top - 1);  }    //弹出栈顶元素  void Pop( Sqstack &s, BiTree &e )  {      if ( s.top == s.base )      {      printf("栈为空\n");      return ;      }      e = *(--s.top);  }    //判断栈是否为空，为空返回1，否则返回0  int StackEmpty( Sqstack s )  {      if ( s.top == s.base )      return 1;      return 0;  }    /*****************栈的操作定义********************/    /*建立二叉树(先序)*/BiTree CreateBiTree(){            char ch;    BiTree T;    ch=getchar();    if(ch=='.')T=NULL;    else{        T = (BiTree)malloc(sizeof(BiTNode));        T->data = ch;        T->lchild = CreateBiTree();        T->rchild = CreateBiTree();    }    return T;//返回根节点}  /*先序遍历二叉树*/void PreOrder(BiTree root){         if(root){       printf("%c ",root->data);       PreOrder(root->lchild);       PreOrder(root->rchild);    }}   /*中序遍历二叉树*/void InOrder(BiTree root){          if(root){      InOrder(root->lchild);       printf("%c ",root->data);       InOrder(root->rchild);    }}  /*后序遍历二叉树*/void PostOrder(BiTree root){        if(root){       PostOrder(root->lchild);       PostOrder(root->rchild);       printf("%c ",root->data);    }} /*按层次遍历二叉树*/void LevelOrder(BiTree root){    int front,rear;    BiTree p;    BiTree *Queen;Queen=(BiTree *)malloc(sizeof(BiTree *)*1000);        front=rear=0;    Queen[++rear]=root;   while(front != rear)    {             p=Queen[++front];        printf("%c ",p->data);        if(p->lchild)    Queen[++rear]=p->lchild;            if(p->rchild)    Queen[++rear]=p->rchild;            }free(Queen); //释放队列空间} /*非递归中序遍历二叉树*/void InOrder1(BiTree root)  {      BiTree p = root;      Sqstack s;      InitStack(s);              while ( p || !StackEmpty(s) )      {     if ( p )          {         Push(s,p);        p = p->lchild;    }      else  {  Pop(s,p);     printf("%c ",p->data);    p = p->rchild;    }    }  }   /*非递归后序遍历二叉树*/void  PostOrder1(BiTree root){BiTree p=root,q=NULL;Sqstack s;      InitStack(s); while(p!=NULL|| (!StackEmpty(s)) ){while(p!=NULL){Push(s,p);        p = p->lchild;   }if(!StackEmpty(s)){ GetTop(s,p);if((p->rchild==NULL)||(p->rchild==q)){printf("%c ",p->data);Pop(s,p);q=p;p=NULL;} elsep=p->rchild; }}}     /*逆时针旋转90度打印二叉树*/void PrintTree(BiTree bt,int nLayer){int i;if(bt==NULL)  return;PrintTree(bt->rchild,nLayer+1);for(i=0;i<nLayer;i++)printf("   ");printf("%c\n",bt->data); PrintTree(bt->lchild,nLayer+1); }    int  main(void){    BiTree root;     printf("请前序创建二叉树：(若孩子节点为NULL，则以字符“.”代替)\n");    root = CreateBiTree();//建立二叉树   printf("\n您输入的二叉树为:(逆时针旋转90度)\n\n");PrintTree(root,0); printf("\n递归前序遍历:   ");PreOrder(root); printf("\n递归中序遍历:   ");InOrder(root); printf("\n递归后序遍历:   ");    PostOrder(root);  printf("\n\n按照层次遍历:   ");    LevelOrder(root);  printf("\n\n非递归中序遍历: ");    InOrder1(root); printf("\n非递归后序遍历: ");    PostOrder1(root);       printf("\n\n");return 0;}

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