【数据结构】huffman编码

#define DeBUG
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#include <string>
#include <set>
#include <sstream>
#include <map>
#include <bitset>
using namespace std ;
#define zero {0}
#define INF 0x3f3f3f3f
#define EPS 1e-6
typedef long long LL;
const double PI = acos(-1.0);
//#pragma comment(linker,"/STACK:102400000,102400000")
inline int sgn(double x)
{
    return fabs(x) < EPS ? 0 : (x < 0 ? -1 : 1);
}
struct Node
{
    Node *left,*right;//左右孩子
    Node *parent;//父节点
    bool flag;//是否为插入节点
    int value;//节点值
    Node() {}
    Node(int x,Node *l,Node *r,Node *p,bool isnode)
    {
        value = x;
        left = l;
        right = r;
        parent = p;
        flag = isnode;
    }
    bool lessthan(const Node *pnode) const//用于优先队列的比较
    {
        return value > pnode->value;
    }
};
struct nodePointerComparer
{
    nodePointerComparer() {}
    bool operator ()(const Node *a,const Node *b) const
    {
        return a->lessthan(b);
    }
};
void layerOrder(Node *p)
{
    if (p != NULL)
    {
        queue<Node *>st;
        st.push(p);
        while (!st.empty())
        {
            Node *Now = st.front();
            st.pop();
            if ( Now->parent != NULL)
            {
                if (Now->parent->right == Now)
                    printf("(%d->%d) ",Now->parent->value,Now->value);
                else
                    printf("(%d<-%d) ",Now->value);
            }
            else
                printf("(%d-%d) ",Now->value);
            if (Now->left != NULL)
            {
                st.push(Now->left);
            }
            if (Now->right != NULL)
            {
                st.push(Now->right);
            }
        }
    }
    printf("\n");
}
char code[100];
void dfs(Node *p,int deep)
{
    if (p->left != NULL)
    {
        code[deep] = '0';
        dfs(p->left,deep + 1);
        code[deep] = '\0';
    }
    if (p->right != NULL)
    {
        code[deep] = '1';
        dfs(p->right,deep + 1);
        code[deep] = '\0';
    }
    if (p->right == NULL && p->left == NULL)
    {
        if (p->flag)
            printf("%d: %s\n",p->value,code);
    }
}
int main()
{
#ifdef DeBUGs
    freopen("C:\\Users\\Sky\\Desktop\\1.in","r",stdin);
#endif

    printf("输入节点：\n");
    int v;
    priority_queue<Node *,vector<Node *>,nodePointerComparer>pQ;
    while (scanf("%d",&v) + 1)
    {
        pQ.push(new Node(v,NULL,true));
    }
    Node *root;
    Node *l,*r;
    while (!pQ.empty())
    {
        if (!pQ.empty())
        {
            l = pQ.top();
            pQ.pop();
        }
        if (!pQ.empty())
        {
            r = pQ.top();
            pQ.pop();
        }
        if (r)
        {
            root = new Node(l->value + r->value,l,r,false);
            l->parent = root;
            r->parent = root;
            pQ.push(root);
        }
        else
        {
            root = l;
        }
        l = r = NULL;
    }
    printf("生成huffman树层序遍历：\n");
    layerOrder(root);
    printf("生成编码：\n");
    memset(code,sizeof(code));
    dfs(root,0);
    return 0;
}

原文地址：https://www.jb51.cc/datastructure/383028.html