数据结构 二叉树的非递归遍历

#include <stdio.h>#include <stdlib.h>#define STACT_INIT_SIZE   100#define STACTINCREMENT    10#define OK            1#define ERROR         0#define OVERFLOW     -2typedef char TElemType;typedef struct BiNode{TElemType data;struct BiNode *lchild,*rchild;}BiNode, *BiTree;typedef BiTree SElemType;typedef struct {SElemType *base;SElemType *top;int stacksize;}SqStack;int InitStack(SqStack &S){S.base = (SElemType *)malloc(STACT_INIT_SIZE * sizeof(SElemType));if (!S.base){exit(OVERFLOW);}S.top = S.base ;S.stacksize = STACT_INIT_SIZE;return OK;}int Push(SqStack &S, SElemType e){if (S.top - S.base >= S.stacksize){S.base = (SElemType*)realloc(S.base , (S.stacksize + STACTINCREMENT) * sizeof(SElemType));if (!S.base){exit(OVERFLOW);}S.top = S.base + S.stacksize ;S.stacksize += STACTINCREMENT;}*S.top++ = e;return OK;}int Pop(SqStack &S, SElemType &e){if (S.base == S.top){return ERROR;}e = *--S.top;return OK;}int GetTop(SqStack S,SElemType &e){if (S.base == S.top){return ERROR;}e = *(S.top-1);return OK;}int StackEmpty(SqStack S){if (S.top == S.base ){return 1;}return 0;}void Create_BiTree(BiTree &T){TElemType ch;scanf("%c",&ch);if (ch == '#'){T = NULL;}else{T = (BiTree)malloc(sizeof(BiNode));if (!T){exit(OVERFLOW);}T->data = ch;Create_BiTree(T->lchild);Create_BiTree(T->rchild);}}void PreOrderTraverse1(BiTree T){//先序遍历的递归调用1SqStack S;BiTree p = T;InitStack(S);Push(S,p);while (!StackEmpty(S)){while (GetTop(S,p) && p){printf("%c",p->data);Push(S,p->lchild);}Pop(S,p);if (!StackEmpty(S)){Pop(S,p);Push(S,p->rchild);}}}void PreOrderTraverse2(BiTree T){//先序遍历的递归调用2SqStack S;BiTree p = T;InitStack(S);while (p || !StackEmpty(S)){if (p){printf("%c",p->data);Push(S,p);p = p->lchild;}else{Pop(S,p);p = p->rchild;}}}void InOrderTraverse1(BiTree T){//中序遍历的非递归调用1SqStack S;BiTree p = T;InitStack(S);Push(S,p);while (!StackEmpty(S)){while (GetTop(S,p) && p){Push(S,p->lchild);}Pop(S,p);if (!StackEmpty(S)){Pop(S,p);printf("%c",p->data);Push(S,p->rchild);}}}void InOrderTraverse2(BiTree T){//中序遍历的非递归调用2SqStack S;BiTree p = T;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;}}}void PostOrderTraverse1(BiTree T){BiTree p,p1;SqStack S;p = T;p1 = NULL;InitStack(S);while (p || !StackEmpty(S)){if (p){Push(S,p);//visit,先序p = p->lchild;}else{GetTop(S,p);//visit,中序if (p->rchild == p1){//右子树为空，或者为上一次弹出的子树，则弹出根节点Pop(S,p1);p = NULL;//visit,后序printf("%c",p1->data);}else{p = p->rchild;p1 = NULL;}}}}int main(){BiTree T;Create_BiTree(T);PreOrderTraverse1(T);printf("\n");PreOrderTraverse2(T);printf("\n");InOrderTraverse1(T);printf("\n");InOrderTraverse2(T);printf("\n");PostOrderTraverse1(T);printf("\n");return 0;}