数据结构上机——二叉树

#include <iostream>
#include<stdio.h>
#include<stdlib.h>
using namespace std;

typedef char TelemType;

typedef struct BinaryTreeNode {
TelemType data;
struct BinaryTreeNode *Left;
struct BinaryTreeNode *Right;
} Node;
typedef Node * BinTree;

//创建二叉树,中间节点->左子树->右子树
Node* createBinaryTree() {
Node *p;
TelemType ch;
cin>>ch;
if(ch == '@') {
p = NULL;
} else {
p = (Node*)malloc(sizeof(Node));
p->data = ch;
p->Left  = createBinaryTree();
p->Right = createBinaryTree();
}
return p;
}

//先序遍历
void preOrder(Node* root) {
if( root ) {
cout<<root->data<<' ';
preOrder(root->Left);
preOrder(root->Right);
}
}

//中序遍历
void inOrder(Node* root) {
if( root ) {
inOrder(root->Left);
cout<<root->data<<' ';
inOrder(root->Right);
}
}

//后序遍历
void lastOrder(Node* root) {
if( root ) {
lastOrder(root->Left);
la
4000
stOrder(root->Right);
cout<<root->data<<' ';
}
}
//二叉树的深度
int DepthOfTree(Node* root) {
if(root) {
return DepthOfTree(root->Left) > DepthOfTree(root->Right)?  DepthOfTree(root->Left)+1:DepthOfTree(root->Right)+1;
}
if( root == NULL ) {
return 0;
}
}

//二叉树叶子节点数
int Leafnum(Node* root) {
if(!root) {
return 0;
} else if(  (root->Left == NULL) && (root->Right == NULL) ) {
return 1;
} else {
return  (Leafnum(root->Left) + Leafnum(root->Right)) ;
}
}

int main() {//ABC@@DE@G@@F@@@
BinTree root = NULL;
root = createBinaryTree();
printf("二叉树建立成功");
cout<<"二叉树深度为："<<DepthOfTree(root)<<endl;
cout<<"二叉树叶子节点数为："<<Leafnum(root)<<endl;
cout<<endl;
cout<<"前序遍历结果:"<<endl;
preOrder(root);
cout<<endl;
cout<<"中序遍历结果:"<<endl;
inOrder(root);
cout<<endl;
cout<<"后序遍历结果:"<<endl;
lastOrder(root);
cout<<endl;
return 0;
}
/*ABC@@DE@G@@F@@@
二叉树建立成功二叉树深度为：5
二叉树叶子节点数为：3

前序遍历结果:
A B C D E G F
中序遍历结果:
C B E G D F A
后序遍历结果:
C G E F D B A
Press any key to continue*/

#include <cstdio>
#include <cstring>
const int maxn=105;
char pre[maxn],in[maxn];

struct node{
char data;
node* lch;
node* rch;
};

node* create(int prel,int prer,int inl,int inr){ //创建
if(prel>prer) return NULL;//递归结束条件
node* root=new node;
root->data=pre[prel];
int k;
for(k=inl;k<=inr;k++) if(in[k]==pre[prel]) break;  //每次递归找（子）树根
int numleft=k-inl;
root->lch=create(prel+1,prel+numleft,inl,k-1);
root->rch=create(prel+numleft+1,prer,k+1,inr);
return root;
}

void postorder(node* root){  //输出
if(root==NULL) return;  //递归结束条件
postorder(root->lch);
postorder(root->rch);
printf("%c",root->data);
}

int main(){

while(scanf("%s%s",pre,in)==2){
int n=strlen(pre);
node* root=create(0,n-1,0,n-1);
postorder(root);
printf("\n");
}
return 0;
}