哈夫曼编码（Huffman）

今天看数据结构，看到哈夫曼编码。感觉挺有意思的。哈夫曼树的应用应该很多吧，还刚学，以后多深入看看。

#include <iostream>#include <cstdio>#include <stack>#include <algorithm>#include <queue>//#include <functional>#include <cstring>#define Max 100000000using namespace std;struct node{    int ww;    int parent,left,right;};struct pp{    int m;    int root;    node head[100];};int x[50];string y[50];pp Huffman(int m){    pp shu;    shu.m=m;    int m1=Max,m2=Max;    for (int number=0;number<2*m-1;number++)    {        shu.head[number].ww=-1,shu.head[number].parent=-1,shu.head[number].left=-1,        shu.head[number].right=-1;        if(number<m)        {            shu.head[number].ww=x[number];        }    }    for (int number1=0;number1<m-1;number1++)    {        int x1=-1,x2=-1;        m1=Max,m2=Max;        for (int number2=0;number2<number1+m;number2++)        {            if (shu.head[number2].ww<m1&&shu.head[number2].parent==-1)            {                x2=x1,m2=m1;                x1=number2;                m1=shu.head[number2].ww;            }            else if (shu.head[number2].ww<m2&&shu.head[number2].parent==-1)            {                x2=number2;                m2=shu.head[number2].ww;            }        }        shu.head[x1].parent=m+number1;        shu.head[x2].parent=m+number1;        shu.head[m+number1].left=x1;        shu.head[m+number1].right=x2;        shu.head[m+number1].ww=m1+m2;    }    return shu;}void qian(pp shu,int num,string all){    string p=all;    int flag=0;    if (shu.head[num].left!=-1)    {        flag=1;        all+='0';        qian(shu,shu.head[num].left,all);    }    if (shu.head[num].right!=-1)    {        if (flag==1)all=p;        all+='1';        qian(shu,shu.head[num].right,all);    }    if (shu.head[num].left==-1&&shu.head[num].right==-1)    {        y[num]=all;    }}//用来输出哈夫曼编码的。