二叉树的基本操作

/*
 * @Issue: 二叉树的创建，遍历，删除
 * @Author: 一届书生
 * @LastEditTime: 2020-02-22 15:16:22
 */
#include<iostream>
using namespace std;

// 定义树的基本结构
typedef struct CSNode{
    char data;
    CSNode *left,*right;
}TNode,*Tree;


// 构造二叉树   [先序遍历输入的方法]
void CreateTree(Tree &t){
    char c;
    cin>>c;
    if(c=='#')t=NULL;  
    else{
        t=new TNode;
        t->data=c;
        CreateTree(t->left);
        CreateTree(t->right);
    }
}

//先序遍历[递归]
void PreOrderTraverse(Tree T)
{
    if(T)
    {
        cout<<T->data;
        PreOrderTraverse(T->left);
        PreOrderTraverse(T->right);
    }
}

//中序遍历[递归]
void InOrderTraverse(Tree T)
{
    if(T)
    {
        InOrderTraverse(T->left);
        cout<<T->data;
        InOrderTraverse(T->right);
    }
}

//后序遍历[递归]
void PostOrderTraverse(Tree T)
{
    if(T)
    {
        PostOrderTraverse(T->left);
        PostOrderTraverse(T->right);
        cout<<T->data;
    }
}

// 求二叉树的深度[递归]
int getDepth(Tree t){
    if(t==NULL)
        return 0;
    else{
        int m=getDepth(t->left);
        int n=getDepth(t->right);
        return m>n?m+1:n+1;
    }
}

// 统计二叉树中结点的个数[递归]
int getNodenum(Tree t){
    if(t==NULL)
        return 0;
    else{
        return getNodenum(t->left)+getNodenum(t->right)+1;
    }
}

// 统计二叉树中叶子结点的个数[递归]
int getLeafnum(Tree t){
    if(t==NULL)
        return 0;
    if(!t->left&&!t->right)
        return 1;   //左右子树都不存在，即为叶节点
    else{
        return getLeafnum(t->left)+getLeafnum(t->right);
    }
}

int main(){
    // 样例：AB#CD##E##F#GH###
    Tree t;
    CreateTree(t);
    cout<<endl<<"先序遍历输出：";
    PreOrderTraverse(t);
    cout<<endl<<"中序遍历输出：";
    InOrderTraverse(t);
    cout<<endl<<"后序遍历输出：";
    PostOrderTraverse(t);
    cout<<endl<<"二叉树的深度为："<<getDepth(t);
    cout<<endl<<"结点的个数为："<<getNodenum(t);
    cout<<endl<<"叶子结点的个数为："<<getLeafnum(t);

    return 0;
}