C++用哈夫曼树编码压缩文章报错，请前辈指点

[罗宾范佩西]

引用

#ifndef _HFTREE_
#define _HFTREE_

#include <string>
using namespace std;

template<class Type>
class hfTree {
private:
struct Node
{
Type data;
int weight;
int parent, left, right;
};
Node * elem;
int length;
public:
struct hfCode {
Type data;
string code;
};

hfTree(const Type *x, const int * w, int size);
void getCode(hfCode result[]);
~hfTree() { delete [] elem; }


};


template<class Type>
hfTree<Type>::hfTree(const Type * v, const int * w, int size)
{
const int max = 32767;
int min1, min2;//最小树，次最小树的权值
int x, y;//最小树，次最小树的下标

length = 2 * size;
elem = new Node[length];
//将数表初始化
for (int i = size; i < length; ++i)
{
elem[i].weight = w[i - size];
elem[i].data = v[i - size];
elem[i].parent = elem[i].left = elem[i].right = 0;
}
//归并森林中的树
for (int i = size - 1; i > 0; --i)
{
min1 = min2 = max; x = y = 0;
for (int j = i + 1; j<length; ++j)
if (elem[j].parent == 0)
if (elem[j].weight<min1)
{
min2 = min1; min1 = elem[j].weight; x = y; y = j;
}
else if (elem[j].weight<min2)
{
min2 = elem[j].weight; x = j;
}//第52-61:找出待归并的两棵树
elem[i].weight = min1 + min2;
elem[i].left = x; elem[i].right = y; elem[i].parent = 0;
elem[x].parent = i; elem[y].parent = i;
}
}



template<class Type>
void hfTree<Type>::getCode(hfCode result[])
{
int size = length / 2;
int p, s;//p是s的父节点
for (int i = size; i<length; ++i)
{
result[i - size].data = elem[i].data;
result[i - size].code = " ";
p = elem[i].parent; s = i;
while (p) {
if (elem[p].left == s)
result[i - size].code = "0" + result[i - size].code;
else result[i - size].code = "1" + result[i - size].code;
s = p; p = elem[p].parent;
}
}
}


#endif // !1

#include"hfTree.h"
#include<iostream>
#include <string>
using namespace std;
/*
输入一篇英文文章，统计每个字符出现的次数，
并以此构造哈夫曼树和输出每个字符的哈夫曼编码，
最后输出这篇文章的编码。
*/
int main()
{
struct Wen
{
char abc;
int weight;
}; Wen *elems;
//结点指针保存文章的字符和权重
cout << "请输入一段英文，按回车键结束。" << endl;
string str;
getline(cin, str);

int str_lenth = str.length();
elems=new Wen [str_lenth];
int _length = 0;

for (int j = 0; j < str_lenth; j++)
for (int i = 0; i <= j; i++)
{
if (elems[i].abc== str[j])
{
elems[i].weight++; break;
}
else if(elems[i].abc==0)
elems[i].abc = str[j];
elems[i].weight = 1;
_length++;
}//两次for循环统计文章相同的字符和权重
char *xx = new char[_length];
int *ww = new int[_length];
for (int i = 0; i < _length; i++) {
xx[i] = elems[i].abc;
ww[i] = elems[i].weight;
}//将文章出现的字符和权重保存在两个数组中

hfTree<char>tree(xx, ww, _length);
hfTree<char>::hfCode result [200];

tree.getCode(result);
for (int i = 0; i < _length; ++i)
cout << result[i].data << " " << result[i].code <<endl;
system("pause");
return 0;

}
头文件是引用书里的，希望前辈能指出我的主函数里的错误，编译没有问题，但无法运行。

[赵4老师]

仅供参考：

#include <iostream>
#include <string>
using namespace std;
struct huffTree {
    int parent;
    int lchild;
    int rchild;
    int weight;
    string flag;
};
struct Lowest_node {
    char ch;
    int ch_num;
};
void coding(int length,huffTree *tree,int n,int &a,int &b) {
    int i;
    int r,s;

    r=s=length;
    for (i=0;i<n;i++) {
        if (tree[i].weight<r
         && tree[i].parent==-1) {
            r=tree[i].weight;
            a=i;
        }
    }
    for (i=0;i<n;i++) {
        if (tree[i].weight<s
         && i!=a
         && tree[i].parent==-1) {
            s=tree[i].weight;
            b=i;
        }
    }
}
void frequency(string str) {
    int i,j;
    int length=str.length();
    Lowest_node *node=new Lowest_node[length];

    for (i=0;i<length;i++) node[i].ch_num=0;

    int char_type_num=0;
    for (i=0;i<length;i++) {
        for (j=0;j<char_type_num;j++)
            if (str[i]==node[j].ch
            || ('a'<=node[j].ch && node[j].ch<='z'
                && str[i]+32==node[j].ch))
                break;//
        if (j<char_type_num) node[j].ch_num++;
        else {
            if ('A'<=str[i] && str[i] <= 'Z') node[j].ch=str[i]+32;
            else node[j].ch=str[i];
            node[j].ch_num++;
            char_type_num++;
        }
    }
    for (i=0;i<char_type_num;i++) {
        for (j=i;j<char_type_num;j++) {
            if (node[j].ch_num<node[j+1].ch_num) {
                int temp;
                char ch_temp;
                temp=node[j].ch_num;
                ch_temp=node[j].ch;
                node[j].ch_num=node[j+1].ch_num;
                node[j].ch=node[j+1].ch;
                node[j+1].ch_num=temp;
                node[j+1].ch=ch_temp;
            }
        }
    }
    for (i=0;i<char_type_num;i++)
        cout<<"字符"<<node[i].ch<<"出现了"<<node[i].ch_num<<"次"<<endl;
    huffTree *huff=new huffTree[2*char_type_num-1];
    huffTree temp;
    string *code=new string[2*char_type_num-1];

    for (i=0;i<2*char_type_num-1;i++) {
        huff[i].lchild=-1;
        huff[i].parent=-1;
        huff[i].rchild=-1;
        huff[i].flag=-1;
    }
    for (j=0;j<char_type_num;j++) huff[j].weight=node[j].ch_num;
    int min1,min2;
    for (int k=char_type_num;k<2*char_type_num-1;k++) {
        coding(length,huff,k,min1,min2);
        huff[min1].parent=k;
        huff[min2].parent=k;
        huff[min1].flag="0";
        huff[min2].flag="1";
        huff[k].lchild=min1;
        huff[k].rchild=min2;
        huff[k].weight=huff[min1].weight+huff[min2].weight;
    }
    for (i=0;i<char_type_num;i++) {
        temp=huff[i];
        while (1) {
            code[i]=temp.flag+code[i];
            temp=huff[temp.parent];
            if (temp.parent==-1) break;//
        }
    }
    cout<<"字符串的每个字符huffman编码为："<<endl;
    for (i=0;i<char_type_num;i++) cout<<node[i].ch<<"  "<<code[i]<<endl;
    cout<<"整个字符串的huffman编码为："<<endl;
    for (i=0;i<length;i++) {                                                                                     //S?
        for (j=0;j<char_type_num;j++) {
            if (str[i]==node[j].ch)
                cout<<code[j];
        }
    }
    delete[] node;
    node=NULL;
    delete[] huff;
    huff=NULL;
    delete[] code;
    code=NULL;
}
int main() {
    int length=0;
    string str;
    cout<<"请输入一个字符串：";
    cin>>str;
    frequency(str);
    return 0;
}
//请输入一个字符串：2333abcde
//字符3出现了3次
//字符2出现了1次
//字符a出现了1次
//字符b出现了1次
//字符c出现了1次
//字符d出现了1次
//字符e出现了1次
//字符串的每个字符huffman编码为：
//3  11
//2  000
//a  001
//b  010
//c  011
//d  100
//e  101
//整个字符串的huffman编码为：
//000111111001010011100101

[罗宾范佩西]

引用 1 楼 zhao4zhong1 的回复:

仅供参考：

#include <iostream>
#include <string>
using namespace std;
struct huffTree {
    int parent;
    int lchild;
    int rchild;
    int weight;
    string flag;
};
struct Lowest_node {
    char ch;
    int ch_num;
};
void coding(int length,huffTree *tree,int n,int &a,int &b) {
    int i;
    int r,s;

    r=s=length;
    for (i=0;i<n;i++) {
        if (tree[i].weight<r
         && tree[i].parent==-1) {
            r=tree[i].weight;
            a=i;
        }
    }
    for (i=0;i<n;i++) {
        if (tree[i].weight<s
         && i!=a
         && tree[i].parent==-1) {
            s=tree[i].weight;
            b=i;
        }
    }
}
void frequency(string str) {
    int i,j;
    int length=str.length();
    Lowest_node *node=new Lowest_node[length];

    for (i=0;i<length;i++) node[i].ch_num=0;

    int char_type_num=0;
    for (i=0;i<length;i++) {
        for (j=0;j<char_type_num;j++)
            if (str[i]==node[j].ch
            || ('a'<=node[j].ch && node[j].ch<='z'
                && str[i]+32==node[j].ch))
                break;//
        if (j<char_type_num) node[j].ch_num++;
        else {
            if ('A'<=str[i] && str[i] <= 'Z') node[j].ch=str[i]+32;
            else node[j].ch=str[i];
            node[j].ch_num++;
            char_type_num++;
        }
    }
    for (i=0;i<char_type_num;i++) {
        for (j=i;j<char_type_num;j++) {
            if (node[j].ch_num<node[j+1].ch_num) {
                int temp;
                char ch_temp;
                temp=node[j].ch_num;
                ch_temp=node[j].ch;
                node[j].ch_num=node[j+1].ch_num;
                node[j].ch=node[j+1].ch;
                node[j+1].ch_num=temp;
                node[j+1].ch=ch_temp;
            }
        }
    }
    for (i=0;i<char_type_num;i++)
        cout<<"字符"<<node[i].ch<<"出现了"<<node[i].ch_num<<"次"<<endl;
    huffTree *huff=new huffTree[2*char_type_num-1];
    huffTree temp;
    string *code=new string[2*char_type_num-1];

    for (i=0;i<2*char_type_num-1;i++) {
        huff[i].lchild=-1;
        huff[i].parent=-1;
        huff[i].rchild=-1;
        huff[i].flag=-1;
    }
    for (j=0;j<char_type_num;j++) huff[j].weight=node[j].ch_num;
    int min1,min2;
    for (int k=char_type_num;k<2*char_type_num-1;k++) {
        coding(length,huff,k,min1,min2);
        huff[min1].parent=k;
        huff[min2].parent=k;
        huff[min1].flag="0";
        huff[min2].flag="1";
        huff[k].lchild=min1;
        huff[k].rchild=min2;
        huff[k].weight=huff[min1].weight+huff[min2].weight;
    }
    for (i=0;i<char_type_num;i++) {
        temp=huff[i];
        while (1) {
            code[i]=temp.flag+code[i];
            temp=huff[temp.parent];
            if (temp.parent==-1) break;//
        }
    }
    cout<<"字符串的每个字符huffman编码为："<<endl;
    for (i=0;i<char_type_num;i++) cout<<node[i].ch<<"  "<<code[i]<<endl;
    cout<<"整个字符串的huffman编码为："<<endl;
    for (i=0;i<length;i++) {                                                                                     //S?
        for (j=0;j<char_type_num;j++) {
            if (str[i]==node[j].ch)
                cout<<code[j];
        }
    }
    delete[] node;
    node=NULL;
    delete[] huff;
    huff=NULL;
    delete[] code;
    code=NULL;
}
int main() {
    int length=0;
    string str;
    cout<<"请输入一个字符串：";
    cin>>str;
    frequency(str);
    return 0;
}
//请输入一个字符串：2333abcde
//字符3出现了3次
//字符2出现了1次
//字符a出现了1次
//字符b出现了1次
//字符c出现了1次
//字符d出现了1次
//字符e出现了1次
//字符串的每个字符huffman编码为：
//3  11
//2  000
//a  001
//b  010
//c  011
//d  100
//e  101
//整个字符串的huffman编码为：
//000111111001010011100101

可以看看我写的代码主函数部分是哪错了吗，编译没有提示。

[赵4老师]

代码功能归根结底不是别人帮自己看或讲解或注释出来的；而是被自己静下心来花足够长的时间和精力亲自动手单步或设断点或对执行到某步获得的中间结果显示或写到日志文件中一步一步分析出来的。 提醒：再牛×的老师也无法代替学生自己领悟和上厕所！ 单步调试和设断点调试（VS IDE中编译连接通过以后，按F10或F11键单步执行，按Shift+F11退出当前函数；在某行按F9设断点后按F5执行停在该断点处。）是程序员必须掌握的技能之一。