Question

哈夫曼编码，给跪了，求大神，有错。#include<iostream> #include<string> #include<fstream>

using namespace std;
#define N 100
typedef struct{
float weight;
int parent,lchild,rchild;
}*HTNode,hufftree;
typedef struct{
char co[N];
int start;
}HCode;
int* frequent(string &str,int &n)//统计各个字符出现的频率
{ int i=0,j=0;int *weight=new int[n];string s;
char ch[256]={0};
ifstream in;
in.open("input.txt");
if(!in)
{ cout<<"cannot open input file.\n"; exit(1); }
while(!in.eof())
{getline(in,s); str+=s; }
while(i<str.size())
{ ch[str[i]]++;i++; }
for(i=0;i<256;i++)
{if(ch[i]!=0)//记录过的所有字符
n++;//结点个数n}
for(i=0;i<n;i++)
{ if(ch[i]!=0)
weight[j++]=ch[i];}
in.close();
return weight;
}
void createHT(int *w,HTNode &T,int &n)//建立哈夫曼树
{
int i; T=new hufftree[2*n-1];
for(i=0;i<n;i++)
T[i].weight=w[i];
for(i=0;i<2*n-1;i++)
{T[i].parent=T[i].lchild=T[i].rchild=-1;}
for(i=n;i<2*n-1;i++)
{double min1,min2;
min1=min2=32767;
int p1,p2;p1=p2=-1;
for(int j=0;j<i;j++)
{if(T[j].parent==-1)
{if(T[j].weight<min1)
{min2=min1;p2=p1;min1=T[j].weight;p1=j;}
else if(T[j].weight<min2)
{min2=T[i].weight;p2=j;}}}
T[p1].parent=T[p2].parent=i;
T[i].lchild=p1;
T[i].rchild=p2;
T[i].weight=T[p1].weight+T[p2].weight;
}}
void Huffmancoding(HTNode &T,int &n,char ch[],string &str)
{int c,p,i;
HCode C;string stri;int j,k;
ofstream out("output.txt",ios::trunc);
for (k=0;k<256;k++)
{if (ch[k]!=0)
{ out<<(char)k<<":";
while (T[i].weight!=ch[k])
i++;
T[i].weight=0;ch[k]=i;
C.start=n;c=i;
while((p=T[c].parent)!=-1)
{ if(T[p].lchild==c)
C.co[C.start--]='0';
else
C.co[C.start--]='1';
c=p;
for (j=C.start;j<n;j++)
out<<C.co[j];
out<<endl;
}}
for(int m=0;m<str.size();m++)
{c=ch[str[m]];
C.start=n;
while((p=T[c].parent)!=-1)
{ if(T[p].lchild==c)
C.co[C.start--]='0';
else
C.co[C.start--]='1';
c=p;}
for(j=C.start;j<n;j++)
stri+=C.co[j];
}
out<<stri;
out.close();
}
int main()
{string str;
int n=0,*w;
HTNode T;
char ch[256];
w=frequent(str,n);
createHT(w,T,n);
Huffmancoding(T,n,ch,str);
return 0;}
数据从文件读入，不能运行
因为字数限制本来括号占一行给缩写了，见谅

Answer 1

#include <iostream>
#include <fstream>
#include <string>
using namespace std;
using namespace std;
#define N 100
typedef struct{
    float weight;
    int parent,lchild,rchild;
}*HTNode,hufftree;
typedef struct{
    char co[N];
    int start;
}HCode;
int* frequent(string &str,int &n)
{
    int i=0,j=0;int *weight=new int[n];string s;
    char ch[256]={0};
    ifstream in;
    in.open("input.txt");
    if(!in)
    {
        cout<<"cannot open input file.\n"; exit(1);
    }
    while(!in.eof())
    {
        getline(in,s); str+=s;
    }
    while(i<str.size())
    {
        ch[str[i]]++;i++;
    }
    for(i=0;i<256;i++)
    {
        if(ch[i]!=0)
            n++;
    }
    for(i=0;i<n;i++)
    {
        if(ch[i]!=0)
        weight[j++]=ch[i];
    }
    in.close();
    return weight;
}
void createHT(int *w,HTNode &T,int &n)
{
    int i; T=new hufftree[2*n-1];
    for(i=0;i<n;i++)
    T[i].weight=w[i];
    for(i=0;i<2*n-1;i++)
    {T[i].parent=T[i].lchild=T[i].rchild=-1;}
    for(i=n;i<2*n-1;i++)
    {
        double min1,min2;
        min1=min2=32767;
        int p1,p2;p1=p2=-1;
        for(int j=0;j<i;j++)
        {
            if(T[j].parent==-1)
            {
                if(T[j].weight<min1)
                {
                    min2=min1;p2=p1;min1=T[j].weight;p1=j;
                }
                else if(T[j].weight<min2)
                {
                    min2=T[i].weight;p2=j;
                }
            }
        } 
        T[p1].parent=T[p2].parent=i;
        T[i].lchild=p1; 
        T[i].rchild=p2;
        T[i].weight=T[p1].weight+T[p2].weight;
    }
}
void Huffmancoding(HTNode &T,int &n,char ch[],string &str)
{
    int c,p,i = 0;
    HCode C;string stri;int j,k;
    ofstream out("output.txt",ios::trunc);
    for (k=0;k<256;k++)
    {
        if (ch[k]!=0)
        {
            out<<(char)k<<":";
            while (T[i].weight!=ch[k])
                i++;
            T[i].weight=0;ch[k]=i;
            C.start=n;c=i;
            while((p=T[c].parent)!=-1)
            {
                if(T[p].lchild==c)
                    C.co[C.start--]='0';
                else
                    C.co[C.start--]='1';
                c=p;
                for (j=C.start;j<n;j++)
                out<<C.co[j];
                out<<endl;
            }
        }   
        for(int m=0;m<str.size();m++)
        {
            c=ch[str[m]];
            C.start=n;
            while((p=T[c].parent)!=-1)
            {
                if(T[p].lchild==c)
                    C.co[C.start--]='0';
                else
                    C.co[C.start--]='1';
                c=p;
            }
            for(j=C.start;j<n;j++)
                stri+=C.co[j];
        }
        out << "tst";
        out<<stri;
        out.close();               
    }  
}
int main()
{
    string str;
    int n=0,*w;
    HTNode T;
    char ch[256];
    w=frequent(str,n);
    createHT(w,T,n);
    Huffmancoding(T,n,ch,str);
    return 0;
}

只修改了错误，没有语法错误了，但是没看能不能实现想要的功能

n++;//结点个数n} //你的这个注释误把一个大括号注释掉了

createHT函数最后也少一个大括号，

另外还需要包含string头文件

就这些吧

追问

放到网上来的时候字数不够，把一些东西误删了，运行了功能不能实现。不知道错在哪

Answer 2

文件读入的getline(in,s)中的s没有预分配大小，可以这样String s=new char[1024];
另外，str+=s;中的str为引用类型，你也该在其定义时赋一个比较大的空间，不然怎么可以连接新的字符串s呢，希望对你有帮助