5)二叉树[4]哈夫曼树

#include "iostream"
#include "vector"
using namespace std;

const int maxlen = 100;
#define infinity 65535

struct bnode
{
    int data;//数据
    bnode *lchild,*rchild;
    vector<int>encode;
    bool flags;//使用标志
};

bnode *tree[maxlen];

void initialization(vector<int>A,bnode *tree[maxlen])//初始化
{
    int i;
    for(i=0;i<A.size();i++)
    {
        tree[i] = new bnode;
        tree[i]->data = A[i];//结点的值
        tree[i]->flags = true;//标识未使用
        tree[i]->lchild = NULL;//左子树为空
        tree[i]->rchild = NULL;//右子树为空
    }
}

void merge(int &n,bnode *tree[maxlen])//寻找当前根结点值最小的两个子树将其合并
{
    int i,num1,num2,min1,min2;
    min1 = infinity;
    min2 = infinity;
    for(i=0;i<n;i++)//寻找当前值最小的根节点
    {
        if((tree[i]->data<min1)&&tree[i]->flags)
        {
            min1 = tree[i]->data;
            num1 = i;
        }
    }
    tree[num1]->flags = false;//设置标识已使用过

    for(i=0;i<n;i++)//寻找当前值最小的根节点
    {
        if((tree[i]->data<min2)&&tree[i]->flags)
        {
            min2 = tree[i]->data;
            num2 = i;
        }
    }
    tree[num2]->flags = false;//设置标识已使用过
    //将两个子树合并
    tree[n] = new bnode;
    tree[n]->data = tree[num1]->data + tree[num2]->data;
    tree[n]->flags = true;
    tree[n]->lchild = tree[num1];
    tree[n]->rchild = tree[num2];
    n++;
}

void Huffmantree(int &n,bnode *tree[maxlen])//构造哈夫曼树
{
    int i,num;
    bool flags = true;//标识
    while(flags)
    {
        num = 0;//计数
        for(i=0;i<n;i++)//统计未使用结点数
        {
            if(tree[i]->flags)
            {
                num++;
            }
        }
        if(num>=2)
        {
            merge(n,tree);//合并当前根结点值最小的两棵子树
        }else{
            flags = false;//哈夫曼树构造完成标识
        }
    }
}

void HFTree(bnode *Tree)//中序输出哈夫曼树
{
    if(Tree)
    {
        HFTree(Tree->lchild);
        cout<<Tree->data<<" ";
        HFTree(Tree->rchild);
    }
}

void WPL(bnode *Tree,int &wpl)//求带权路径长度
{
    if(Tree)
    {
        if(Tree->lchild&&Tree->rchild)
        {
            wpl+=Tree->data;
        }
        WPL(Tree->lchild,wpl);
        WPL(Tree->rchild,wpl);
    }
}

void Encode(bnode *Tree,bnode *root)//每个结点进行编码
{
    int i;
    if(Tree)
    {
        if(Tree->lchild)//左子树根结点添加0
        {
            for(i=0;i<Tree->encode.size();i++)
            {
                Tree->lchild->encode.push_back(Tree->encode[i]);
            }
            Tree->lchild->encode.push_back(0);
        }
        if(Tree->rchild)//右子树根结点添加1
        {
            for(i=0;i<Tree->encode.size();i++)
            {
                Tree->rchild->encode.push_back(Tree->encode[i]);
            }
            Tree->rchild->encode.push_back(1);
        }
        Encode(Tree->lchild,root);//左子树继续
        Encode(Tree->rchild,root);//右子树继续
    }
}


void print_Encode(bnode *Tree)//编码先序打印
{
    int i;
    if(Tree)
    {
        cout<<"Data:["<<Tree->data<<"]->Encode:";
        for(i=0;i<Tree->encode.size();i++)
        {
            cout<<Tree->encode[i];
        }
        cout<<endl;
        print_Encode(Tree->lchild);
        print_Encode(Tree->rchild);
    }

}

int main()
{
    int x,n;
    vector<int>Array;
    cout<<"[输入叶子结点,-1输入结束]:"<<endl;
    cout<<"Data:";
    cin>>x;
    while(x!=-1)
    {
        Array.push_back(x);
        cin>>x;
    }
    n = Array.size();
    initialization(Array,tree);//左右子树初始化
    Huffmantree(n,tree);//构造哈夫曼树
    cout<<"哈夫曼树中序输出:";
    HFTree(tree[n-1]);
    cout<<endl;

    int wpl = 0;
    WPL(tree[n-1],wpl);
    cout<<"WPL:"<<wpl<<endl;
    cout<<"Encode:"<<endl;
    Encode(tree[n-1],tree[n-1]);
    print_Encode(tree[n-1]);
    return 0;
}