数据结构实验2(设计哈弗曼编码和译码系统)

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设计一个哈弗曼编码和译码系统, 要求如下:

B——建树：读入字符集和各字符频度，建立哈夫曼树。

T——遍历：先序和中序遍历二叉树。

E——生成编码：根据已建成的哈夫曼树，产生各个字符的哈夫曼编码。

C——编码：输入由字符集中字符组成的任意字符串，利用已生成的哈夫曼编码进行编码，显示编码结果，并将输入的字符串及其编码结果分别保存在磁盘文件textfile.txt和codefile.txt中。

D——译码：读入codefile.txt，利用已建成的哈夫曼树进行译码，并将译码结果存入磁盘文件result.txt。

P——打印：屏幕显示文件textfile.txt，codefile.txt，result.txt。

X——退出。

提示: 修改教材中二叉树结点类BTNode, 增加一个指向双亲的parent域, 修改二叉树类的函数MakeTree设置该域的值. 通过遍历哈夫曼树, 产生每个叶

子结点的哈夫曼编码. 当遍历访问某个叶节点时, 从该叶结点到根的路径可以确定该叶结点所代表的字符的编码.

忘记初始化debug了一晚上, 顺便复习文件操作. 代码用到了优先队列类以及二叉树类.

实现代码:

#include "iostream"
#include "cstdio"
#include "cstring"
#include "algorithm"
#include "cassert"
#include "fstream"
using namespace std;
template <class T>
class PrioQueue
{
public:
	PrioQueue(int mSize = 0);
	~PrioQueue() { delete []q; }
	bool IsEmpty() const { return n == 0; } // 优先队列为空返回true
	bool IsFull() const { return n == maxSize; } // 优先队列为满返回true
	void Append(const T& x); // 优先队列中添加值为x的元素
	void Serve(T& x); // 优先队列中弹出队列中优先权最高的元素, 并赋值给x
private:
	void AdjustDown(int r, int j); // 向下调整
	void AdjustUp(int j); // 向上调整
	void Print();
	T* q;
	int n, maxSize;
	/* data */
};

template <class T>
void PrioQueue<T>::Print()
{
	for(int i = 0; i < n; ++i)
		cout << q[i] << "\t";
	cout << endl;
}

template <class T>
PrioQueue<T>::PrioQueue(int mSize)
{
	maxSize = mSize;
	n = 0;
	q = new T[maxSize];
}

template <class T>
void PrioQueue<T>::AdjustUp(int j)
{
	int i = j;
	T tmp = q[i];
	while(i > 0 && tmp < q[(i - 1) / 2]) {
		q[i] = q[(i - 1) / 2];
		i = (i - 1) / 2;
	}
	q[i] = tmp;
}

template <class T>
void PrioQueue<T>::Append(const T& x)
{
	assert(!IsFull());
	q[n++] = x;
	AdjustUp(n - 1);
}

template <class T>
void PrioQueue<T>::Serve(T& x)
{
	x = q[0];
	q[0] = q[--n];
	AdjustDown(0, n - 1);
}

template <class T>
void PrioQueue<T>::AdjustDown(int r, int j)
{
	int child = 2 * r + 1;
	T tmp = q[r];
	while(child <= j) {
		if(child < j && q[child] > q[child + 1]) child++;
		if(tmp <= q[child]) break;
		q[(child - 1) / 2] = q[child];
		child = 2 * child + 1;
	}
	q[(child - 1) / 2] = tmp;
}

template <class T>
struct BTNode
{
	/* data */
	BTNode() { lChild = rChild = NULL; }
	BTNode(const T &x, const char &y) {
		element = x;
		ch = y;
		lChild = rChild = parent = NULL;
		memset(z, -1, sizeof(z));
	}
	BTNode(const T& x, const char &y, BTNode<T>* l, BTNode<T>* r) {
		element = x;
		ch = y;
		lChild = l;
		rChild = r;
		parent = NULL;
		memset(z, -1, sizeof(z));
	}
	T element;
	BTNode<T>* lChild, *rChild, *parent;
	char ch;
	int val, z[100];
};

template <class T>
class BinaryTree
{
public:
	BinaryTree() { root = NULL; i = -1; }
	bool IsEmpty() const; // 判断是否为空, 是返回true
	void Clear(); // 移去所有结点, 成为空二叉树
	bool Root(T& x) const; // 若二叉树为空, 则x为根的值, 返回true
    BTNode<T>* Root();
    int Size();
    int Count() { return Count(root); }
	void MakeTree(const T& x, const char &y, BinaryTree<T>& left, BinaryTree<T>& right); // 构造一颗二叉树, 根的值为x, left & right为左右子树
	void BreakTree(T& x, BinaryTree<T>& left, BinaryTree<T>& right); // 拆分二叉树为三部分, x为根的值, left & right为左右子树
	void PreOrder(void (*Visit)(T& x)); // 先序遍历二叉树
	void InOrder(void (*Visit)(T& x)); // 中序遍历二叉树
	void PostOrder(void (*Visit)(T& x)); // 后序遍历二叉树
	void Create_code(); // 生成编码
	void Create_code_out(); // 输出编码
	void Code(); // 编码
	void Compile(); // 译码
	void Print();
	BTNode<T>* root;
	/* data */
private:
    int i;
	void Clear(BTNode<T>* t);
    int Size(BTNode<T> *t); // 返回二叉树结点个数
	int Count(BTNode<T> *t); // 返回二叉树只有一个孩子的结点个数
	void PreOrder(void (*Visit)(T &x), BTNode<T> *t);
	void InOrder(void (*Visit)(T &x), BTNode<T> *t);
	void PostOrder(void (*Visit)(T &x), BTNode<T> *t);
	void Create_code(BTNode<T> *t);
	void Create_code_out(BTNode<T> *t);
	void Code(BTNode<T> *t);
	void Compile(BTNode<T> *t);
	void Make(BTNode<T> *t, char a);
};
template <class T>
void Visit(T &x)
{
	cout << x << '\t';
}

template <class T>
BTNode<T>* BinaryTree<T>::Root()
{
    return root;
}
template <class T>
bool BinaryTree<T>::Root(T &x) const
{
	if(root) {
		x = root -> element;
		return true;
	}
	return false;
}

template <class T>
void BinaryTree<T>::Clear(BTNode<T>* t)
{
	if(t) {
		Clear(t -> lChild);
		Clear(t -> rChild);
		cout << "delete" << t -> element << "..." << endl;
		delete t;
	}
}

template <class T>
void BinaryTree<T>::MakeTree(const T& x, const char &y, BinaryTree<T> &left, BinaryTree<T> &right)
{
	if(root || &left == &right) return;
	root = new BTNode<T>(x, y, left.root, right.root);
	if(left.root != right.root) {
		left.root -> parent = root;
		right.root -> parent = root;
		left.root -> val = 0;
		right.root -> val = 1;
	}
	left.root = right.root = NULL;
}

template <class T>
void BinaryTree<T>::BreakTree(T& x, BinaryTree<T>& left, BinaryTree<T>& right)
{
	if(!root || &left == &right || left.root || right.root) return;
	x = root -> element;
	left.root = root -> lChild;
	right.root = root -> rChild;
	delete root;
	root = NULL;
}

template <class T>
void BinaryTree<T>::PreOrder(void (*Visit)(T& x))
{
	cout << "先序遍历为:" << endl;
	PreOrder(Visit, root);
	cout << endl;
}
template <class T>
void BinaryTree<T>::PreOrder(void (*Visit)(T& x), BTNode<T>* t)
{
	if(t) {
		Visit(t -> element);
		PreOrder(Visit, t -> lChild);
		PreOrder(Visit, t -> rChild);
	}
}

template <class T>
void BinaryTree<T>::InOrder(void (*Visit)(T& x))
{
	cout << "中序遍历为:" << endl;
	InOrder(Visit, root);
	cout << endl;
}
template <class T>
void BinaryTree<T>::InOrder(void (*Visit)(T& x), BTNode<T>* t)
{
	if(t) {
		InOrder(Visit, t -> lChild);
		Visit(t -> element);
		InOrder(Visit, t -> rChild);
	}
}

template <class T>
void BinaryTree<T>::PostOrder(void (*Visit)(T& x))
{
	cout << "后序遍历为:" << endl;
	PostOrder(Visit, root);
	cout << endl;
}
template <class T>
void BinaryTree<T>::PostOrder(void (*Visit)(T& x), BTNode<T>* t)
{
	if(t) {
		PostOrder(Visit, t -> lChild);
		PostOrder(Visit, t -> rChild);
		Visit(t -> element);
	}
}

template <class T>
int BinaryTree<T>::Size()
{
	return Size(root);
}
template <class T>
int BinaryTree<T>::Size(BTNode<T> *t)
{
	if(!t) return 0;
	return Size(t -> lChild) + Size(t -> rChild) + 1;
}

template <class T>
int BinaryTree<T>::Count(BTNode<T> *t)
{
	if(!t) return 0;
	if(((t -> lChild) && (!t -> rChild)) || ((!t -> lChild) && (t -> rChild))) return 1;
	return Count(t -> lChild) + Count(t -> rChild);
}

template <class T>
class HfmTree: public BinaryTree<T>
{
public:
	operator T() const{ return weight; }
	T getW() { return weight; }
	void putW(const T &x) { weight = x; }
	void SetNull() { BinaryTree<T>::root = NULL; }
private:
	T weight;
};

template <class T>
HfmTree<T> CreatHfmTree(T w[], char q[], int n)
{
	PrioQueue<HfmTree<T> > pq(n);
	HfmTree<T> x, y, z, zero;
	for(int i = 0; i < n; ++i) {
		z.MakeTree(w[i], q[i], x, y);
		z.putW(w[i]);
		pq.Append(z);
		z.SetNull();
	}
	for(int i = 1; i < n; ++i) {
		pq.Serve(x);
		pq.Serve(y);
		z.MakeTree(x.getW() + y.getW(), 'e', x, y);
		z.putW(x.getW() + y.getW());
		pq.Append(z);
		z.SetNull();
	}
	pq.Serve(z);
	return z;
}

HfmTree<int> HfmT;
int num;

void Make_HfmT()
{
	char s[100];
	int w[100];
	cout << "请输入字符个数:" << endl;
	cin >> num;
	cout << "请输入权值:" << endl;
	for(int i = 0; i < num; ++i)
		cin >> w[i];
	cout << "请输入相应字符集:" << endl;
	cin >> s;
	HfmT = CreatHfmTree(w, s, num);
}
void Traversal_HfmT()
{
	HfmT.PreOrder(Visit);
	HfmT.InOrder(Visit);
	HfmT.PostOrder(Visit);
}

template <class T>
void BinaryTree<T>::Create_code()
{
	Create_code(root);
}

template <class T>
void BinaryTree<T>::Create_code(BTNode<T> *t)
{
	if(t) {
		if(t -> parent) {
			for(int j = 0; j <= i; ++j)
				t -> z[j] = t -> parent -> z[j]; // 复制双亲编码域
			i++;
			t -> z[i] = t -> val; // 编码中加入自己编码
		}
		Create_code(t -> lChild);
		Create_code(t -> rChild);
		i--;
	}
}

template <class T>
void BinaryTree<T>::Create_code_out()
{
	Create_code_out(root);
}

template <class T>
void BinaryTree<T>::Create_code_out(BTNode<T> *t)
{
	if(t) {
		if(t -> lChild == t -> rChild) {
			cout << t -> ch << ':';
			int i = 0;
			while(t -> z[i] != -1) {
				cout << t -> z[i];
				i++;
			}
			cout << endl;
		}
		Create_code_out(t -> lChild);
		Create_code_out(t -> rChild);
	}
}

template <class T>
void BinaryTree<T>::Code()
{
	Code(root);
}

template <class T>
void BinaryTree<T>::Code(BTNode<T> *t)
{
	ofstream outt("textfile.txt");
	if(!outt) {
		cout << "Open textfile.txt failed." << endl;
		return ;
	}
	ofstream outc("codefile.txt", ios::trunc);
	if(!outc) {
		cout << "Open codefile.txt failed." << endl;
		return ;
	}
	outc.close();
	char s[100];
	cout << "请输入由字符集组成的任意字符串:" << endl;
	cin >> s;
	outt << s;
	outt.close();
	int len = strlen(s);
	cout << "编码为:" << endl;
	for(int i = 0; i < len; ++i)
		Make(root, s[i]);
	cout << endl;
}

template <class T>
void BinaryTree<T>::Make(BTNode<T> *t, char a)
{
	int i = 0;
	if(t) {
		if(t -> ch == a) {
			ofstream outc("codefile.txt", ios::app);
			while(t -> z[i] != -1) {
				cout << t -> z[i];
				outc << t -> z[i];
				i++;
			}
			outc.close();
			return ;
		}
		Make(t -> lChild, a);
		Make(t -> rChild, a);
	}
}

template <class T>
void BinaryTree<T>::Compile()
{
	Compile(root);
}

template<class T>
void BinaryTree<T>::Compile(BTNode<T> *t)
{
    ifstream inf("codefile.txt");
    if(!inf) {
        cout << "Open codefile.txt failed." << endl;
        return;
    }
    ofstream outs("result.txt",ios::trunc);
    if(!outs) {
        cout << "Open result.txt failed." << endl;
        return;
    }
    outs.close();
    char *re;
    char tmp;
    int n = 0;
    while(inf.get(tmp) != '\0') n++;
    inf.close();
    re = new char[n+1];
    int n2 = 0;
    ifstream in("codefile.txt");
    if(!in) {
        cout<<"Open codefile.txt failed." << endl;
        return;
    }
    while(in.get(tmp) != '\0') re[n2++] = tmp;
    BTNode<T> *c;
    cout << "译码为 :";
    int n3 = 0;
    while(n3 < n) {
        while(t) {
            c = t;
            if(re[n3] == '0') // 左0右1根据0或1向左走向右走直到叶子结点
                t = t -> lChild;
            else
                t = t -> rChild;
            n3++;
        }
        ofstream outs("result.txt", ios::app);
        if(!outs) {
            cout << "Open result.txt failed." << endl;
            return;
        }
        cout << c -> ch;
        outs << c -> ch;
        outs.close();
        t = root;
        n3--;
    }
    cout << endl;
}

void Print()
{
	char ch;
	ifstream a("textfile.txt");
	ifstream b("codefile.txt");
	ifstream c("result.txt");
	if(!a) {
		cout << "Open textfile.txt failed." << endl;
		return ;
	}
	if(!b) {
		cout << "Open codefile.txt failed." << endl;
		return ;
	}
	if(!c) {
		cout << "Open result.txt failed." << endl;
		return ;
	}
	cout << "textfile.txt内容为:" << endl;
	while(a.get(ch) != '\0') cout << ch;
	cout << endl;
	cout << "codefile.txt内容为:" << endl;
	while(b.get(ch) != '\0') cout << ch;
	cout << endl;
	cout << "result.txt内容为:" << endl;
	while(c.get(ch) != '\0') cout << ch;
	cout << endl;
	a.close();
	b.close();
	c.close();
}

void Menu()
{
	cout << "欢迎使用哈夫曼编码和译码系统" << endl;
	cout << "****************************" << endl;
	cout << "************菜单************" << endl;
	cout << "***********B-建树***********" << endl;
	cout << "***********T-遍历***********" << endl;
	cout << "*********E-生成编码*********" << endl;
	cout << "***********C-编码***********" << endl;
	cout << "***********D-译码***********" << endl;
	cout << "***********P-打印***********" << endl;
	cout << "***********X-退出***********" << endl;
	cout << "****************************" << endl;
}

int main(int argc, char const *argv[])
{
	char ch;
	Menu();
	while(cin >> ch && ch != 'X') {
		switch(ch) {
			case 'B': {
				Make_HfmT();
				HfmT.Create_code();
				break;
			}
			case 'T': {
				Traversal_HfmT();
				break;
			}
			case 'E': {
				cout << "编码为:" << endl;
				HfmT.Create_code_out();
				break;
			}
			case 'C': {
				HfmT.Code();
				break;
			}
			case 'D': {
				HfmT.Compile();
				break;
			}
			case 'P': {
				Print();
				break;
			}
			default: {
				cout << "输入有误, 请重新输入." << endl;
				break;
			}
		}
		Menu();
	}
	return 0;
}

数据结构实验2(设计哈弗曼编码和译码系统)

标签：

原文地址：http://blog.csdn.net/gkhack/article/details/49594015