二叉树的创立和遍历:
#include<stdio.h>
#include<stdlib.h>
#define OK 1
#define OVERFLOW -2
typedef int Status;
typedef char ElemType;
typedef struct BiNode
{
ElemType data;
struct BiNode* lchild, * rchild;
}BiTNode, *BiTree;
Status Create_Tree(BiTree *T); // 创立
Status PreBiTree_Traverse(BiTree T); // 结构和遍历思维:递归
Status InBiTree_Traverse(BiTree T);
Status PostBiTree_Traverse(BiTree T);
int main()
{
BiTree T;
int n;
printf("请输出字符(# 示意空指针):");
Create_Tree(&T);
printf("1. 前序遍历 2. 中序遍历 3. 后序遍历 \n");
printf("请输出遍历形式:");
scanf("%d", &n);
switch (n)
{case 1:PreBiTree_Traverse(T); break;
case 2:InBiTree_Traverse(T); break;
case 3:PostBiTree_Traverse(T); break;
}
return 0;
}
Status Create_Tree(BiTree *T)// 前序结构
{
char ch;
scanf("%c", &ch);
if (ch == '#') // 用 #代表 NULL,即虚结点
{*T = NULL;}
else
{*T = (BiTree)malloc(sizeof(BiTNode));
if (!*T)
exit(OVERFLOW);
(*T)->data = ch;
Create_Tree(&(*T)->lchild);
Create_Tree(&(*T)->rchild);
}
return OK;
}
Status PreBiTree_Traverse(BiTree T) // 前序遍历
{if (T == NULL)
return OVERFLOW;
printf("二叉树的数据为:%c\n", T->data);
PreBiTree_Traverse(T->lchild);
PreBiTree_Traverse(T->rchild);
return OK;
}
Status InBiTree_Traverse(BiTree T) // 中序遍历
{if (T == NULL)
return OVERFLOW;
InBiTree_Traverse(T->lchild);
printf("二叉树的数据为:%c\n", T->data);
InBiTree_Traverse(T->rchild);
return OK;
}
Status PostBiTree_Traverse(BiTree T) // 后序遍历
{if (T == NULL)
return OVERFLOW;
PostBiTree_Traverse(T->lchild);
PostBiTree_Traverse(T->rchild);
printf("二叉树的数据为:%c\n", T->data);
return OK;
}