数据结构——链式二叉树

 

#include <iostream>
using namespace std;

typedef struct treenode
{
    struct treenode *left;
    char data;
    struct treenode *right;
}Treenode,* Treep;

//初始化二叉树
void init_tree(Treep &root)
{
    root=NULL;
    cout<<"初始化成功!"<<endl;
}
//创建二叉树
void creat_tree(Treep &rt)
{
    char ch;
    ch=getchar();
    if('#'==ch)
        rt=NULL;
    else
    {
        rt=(Treep )malloc(sizeof(Treenode));
        rt->data=ch;
        creat_tree(rt->left);        //构造左子树
        creat_tree(rt->right);    //构造右子树    
    }
}
//前序遍历二叉树
void pre_order(Treep &rt)
{
    if(rt!=NULL)
    {
        cout<<rt->data<<"  ";
        pre_order(rt->left);
        pre_order(rt->right);
    }
}
//中序遍历二叉树 

void mid_order(Treep &rt)
{
    if(rt!=NULL)
    {
        mid_order(rt->left);
        cout<<rt->data<<"  ";
        mid_order(rt->right);
    }
}

//后序遍历二叉树
void back_order(Treep &rt)
{
    if(rt!=NULL)
    {
        back_order(rt->left);
        back_order(rt->right);
        cout<<rt->data<<"  ";
    }
}

//层序遍历
void leve_lorder(Treep &rt)
{
    Treep q[100];        //指针数组，存放每个节点的地址
    q[0]=rt;
    int front=0,rear=1;
    while(front<rear)
    {
        if(q[front])
        {
            cout<<q[front]->data<<" ";
            if(q[front]->left)
                q[rear++]=q[front]->left;
            if(q[front]->right)
                q[rear++]=q[front]->right;
            front++;
        }
    }
}

//求二叉树的深度
int depth_tree(Treep &rt)
{
    int depth1=0,depth2=0;
    if(NULL==rt)
        return 0;
    else
    {
        depth1=depth_tree(rt->left);
        depth2=depth_tree(rt->right);
        return (depth1>depth2) ? (depth1+1) : (depth2+1);
    }
}
//求二叉树的节点个数
int leaf_tree(Treep &rt)
{
    if(rt)
    {
        if(rt->left==NULL && rt->right==NULL)
        {
            return 1;
        }
        return ( leaf_tree(rt->left) + leaf_tree(rt->right) + 1 );
    }
    else 
    {
        return 0;
    }
}

//查找二叉树中是否存在某元素
int seach_tree(Treep &rt,char key)
{
    if(rt==NULL) 
        return 0; 
    else 
    { 
        if(rt->data==key) 
        {
            return 1;
        }
        else
        {
            if(seach_tree(rt->left,key) || seach_tree(rt->right,key))
                return 1;    //如果左右子树有一个搜索到，就返回1
            else
                return 0;    //如果左右子树都没有搜索到，返回0
        }
    }
}
//销毁二叉树
int  destroy_tree(Treep &root)
{
    if(root==NULL)
    {
        return 0;
    }
    else
    {
        if(root->left)
        destroy_tree(root->left);
        if(root->right)
        destroy_tree(root->right);
        free(root);
        root=NULL;    //释放内存后的指针要指向NULL
        return 1;
    }
}
//更改某节点的值
void assign_tree(Treep &rt,char c,char value)
{
    if(rt!=NULL)
    {
        if(c==rt->data)
            rt->data=value;
        assign_tree(rt->left,c,value);
        assign_tree(rt->right,c,value);
    }
}

//求双亲

void parent_tree(Treep &rt,char value)
{
    if(rt!=NULL)  
    {
        if(value==rt->data)
        {
            cout<<"此节点是根节点!"<<endl;
        }
        if( (rt->left!=NULL && rt->left->data==value ) || (rt->right!=NULL && rt->right->data==value) )
            cout<<rt->data<<endl;
        else
        {
            parent_tree(rt->left,value);
            parent_tree(rt->right,value);
        }
    }
}

//求左孩子
void leftchild_tree(Treep &rt ,char value )
{
    if(rt!=NULL)
    {
        if(value==rt->data)
        {
            if(rt->left)
                cout<<rt->left->data<<endl;
            else
                cout<<"左孩子为空!"<<endl;
        }
        else
        {
            leftchild_tree(rt->left ,value );
            leftchild_tree(rt->right ,value );
        }
    }
}
//求右孩子
void rightchild_tree(Treep &rt ,char value )
{
    if(rt!=NULL)
    {
        if(value==rt->data)
        {
            if(rt->right)
                cout<<rt->right->data<<endl;
            else
                cout<<"右孩子为空!"<<endl;
        }
        else
        {
            rightchild_tree(rt->left ,value );
            rightchild_tree(rt->right ,value );
        }
    }
}
//求左兄弟
void leftbrother_tree(Treep &rt ,char value )
{
    if(rt!=NULL)
    {
        if(value==rt->data)
        {
            cout<<"此节点是根节点!"<<endl;
        }
        if(rt->left!=NULL && value==rt->left->data)
        {
                cout<<"此节点就是左孩子!"<<endl;
        }
        else if(rt->left!=NULL && value==rt->right->data)
        {
            if(rt->left)
                cout<<rt->left->data<<endl;
            else
                cout<<"左兄弟为空!"<<endl;
        }
        else
        {
            leftbrother_tree(rt->left ,value );
            leftbrother_tree(rt->right ,value );
        }
    }
}

//求右兄弟
void rightbrother_tree(Treep &rt ,char value )
{
    if(rt!=NULL)
    {
        if(value==rt->data)
        {
            cout<<"此节点是根节点!"<<endl;
        }
        if(rt->right!=NULL && value==rt->right->data)
        {
                cout<<"此节点就是右孩子!"<<endl;
        }
        else if(rt->left!=NULL && value==rt->left->data)
        {
            if(rt->right)
                cout<<rt->right->data<<endl;
            else
                cout<<"左兄弟为空!"<<endl;
        }
        else
        {
            rightbrother_tree(rt->left ,value );
            rightbrother_tree(rt->right ,value );
        }
    }
}

//删除子树
void delete_tree(Treep &rt,char ch,int bl)
{
    if(rt!=NULL)
    {
        if(ch==rt->data)
        {
            if(!bl)
                rt->left=NULL;
            else
                rt->right=NULL;
        }
        else
        {
            delete_tree(rt->left, ch, bl);
            delete_tree(rt->right, ch, bl);
        }
    }
}

//插入子树
void insert_tree(Treep &rt1,char ch,int bl,Treep &rt2)
{
    if(rt1!=NULL)
    {
        if(ch==rt1->data)
        {
            if(!bl)
            {
                if( NULL==rt1->left)
                {
                    rt1->left=rt2;
                }
                else
                {
                    cout<<ch<<"的左节点非空!"<<endl;
                }
            }
            else
            {
                if(NULL==rt1->right)
                {
                    rt1->right=rt2;
                }
                else
                {
                    cout<<ch<<"的右节点非空!"<<endl;
                }
            }
        }
        else
        {
            insert_tree(rt1->left, ch, bl,rt2);
            insert_tree(rt1->right, ch, bl,rt2);
        }
    }
}

int main()
{
    Treep root;
    init_tree(root);        //初始化树
    cout<<"请输入二叉树,空值以#代表，输完要以Ctrl+Z表示结束，否则影响下个树的创建!:"<<endl;
    creat_tree(root);        //创建二叉树

    //前序遍历二叉树
    cout<<"前序遍历序列是:"<<endl;
    pre_order(root);
    cout<<endl;

    //中序遍历二叉树
    //cout<<"中序遍历序列是："<<endl;
    //mid_order(root);
    //cout<<endl;

    //后序遍历二叉树
    //cout<<"后序遍历序列是："<<endl;
    //back_order(root);
    //cout<<endl;

    //层序遍历二叉树
    //cout<<"层序遍历序列是："<<endl;
    //leve_lorder(root);
    //cout<<endl;

    //求二叉树的深度
    //cout<<"二叉树的深度："<<endl;
    //cout<<depth_tree(root);
    //cout<<endl;

    //查找二叉树中是否存在某元素
    /*
    cout<<"输入要查找的元素!"<<endl;
    char ch;
    cin>>ch;
    if(seach_tree(root,ch)==1)
        cout<<"yes!"<<endl;
    else
        cout<<"no!"<<endl;
    */

    //更改节点的值
    /*
    cout<<"输入你要改变的值和要改成的值:"<<endl;
    char ch,value;
    cin>>ch>>value;
    assign_tree(root,ch,value);
    pre_order(root);
    cout<<endl;
    */
    //求双亲
    //cout<<"你要找谁的双亲:"<<endl;
    //char value;
    //cin>>value;
    //parent_tree(root ,value );

    //求左孩子
    //cout<<"你要找谁的左孩子:"<<endl;
    //char value;
    //cin>>value;
    //leftchild_tree(root ,value );
    
    //求右孩子
    //cout<<"你要找谁的右孩子:"<<endl;
    //char value;
    //cin>>value;
    //rightchild_tree(root ,value );

    //求左兄弟
    //cout<<"你要找谁的左兄弟:"<<endl;
    //char value;
    //cin>>value;
    //leftbrother_tree(root ,value );

    //求右兄弟
    //cout<<"你要找谁的右兄弟:"<<endl;
    //char value;
    //cin>>value;
    //rightbrother_tree(root ,value );

    //cout<<"你要删除谁的子树:"<<endl;
    //char value;
    //cin>>value;
    //delete_tree(root, value, 1);
    //pre_order(root);
    //cout<<endl;

    //Treep root2;
    //init_tree(root2);        //初始化树
    //cout<<"请输入二叉树,空值以#代表:"<<endl;
    //creat_tree(root2);        //创建二叉树
    //cout<<"前序遍历序列是:"<<endl;
    //pre_order(root2);
    //cout<<endl;

    //cout<<"你要插入谁的子树:"<<endl;
    //char value;
    //cin>>value;
    //insert_tree(root,value,1,root2);
    //pre_order(root);
    //cout<<endl;
    
    //求叶子结点个数
    cout<<"结点个数:"<<endl;
    cout<<leaf_tree(root)<<endl;


    cout<<"销毁二叉树:"<<endl;
    if(destroy_tree(root))
        cout<<"销毁成功!"<<endl;
    else
        cout<<"空树，销毁不成功!"<<endl;
    return 0;
}