2024/12/3日工作总结

完成数据结构pta实验7-1 哈夫曼树哈夫曼编码

输入一组整型权值，构建哈夫曼树，实现哈夫曼编码，并输出带权路径长度。

输入格式:
第一行输入叶子结点个数，接着依次输入权值。若叶子数为0或1，则输出error

输出格式:
输出哈夫曼编码，输出带权路径长度。

输入样例:
在这里给出一组输入。例如：

8
5 29 7 8 14 23 3 11
输出样例:
在这里给出相应的输出。例如：

5编码为0001
29编码为10
7编码为1110
8编码为1111
14编码为110
23编码为01
3编码为0000
11编码为001
WPL:271

点击查看代码

#include <iostream>
#include <cstring>
using namespace std;

typedef char** HuffmanCode;
typedef struct {
    int weight;
    int lchild, rchild, parent;
} HTNode, *HuffmanTree;

// 寻找最小值
void findMinimum(HuffmanTree HT, int pos, int &s1, int &s2) {
    s1 = -1; s2 = -1;
    for (int i = 1; i < pos; ++i) {
        if (HT[i].parent == 0) {
            if (s1 == -1 || HT[i].weight < HT[s1].weight) {
                s2 = s1;
                s1 = i;
            } else if (s2 == -1 || HT[i].weight < HT[s2].weight) {
                s2 = i;
            }
        }
    }
}

// 创建哈夫曼树
void createHuffmanTree(HuffmanTree &HT, int n) {
    if (n <= 1) return;
    int m = 2 * n - 1;
    HT = new HTNode[m + 1];
    for (int i = 1; i <= m; ++i) {
        HT[i].weight = 0;
        HT[i].parent = 0;
        HT[i].lchild = 0;
        HT[i].rchild = 0;
    }
    for (int i = 1; i <= n; i++) {
        cin >> HT[i].weight;
    }
    for (int i = n + 1; i <= m; i++) {
        int s1, s2;
        findMinimum(HT, i, s1, s2);
        HT[s1].parent = i;
        HT[s2].parent = i;
        HT[i].lchild = s1;
        HT[i].rchild = s2;
        HT[i].weight = HT[s1].weight + HT[s2].weight;
    }
}

// 创建哈夫曼编码
void createHuffmanCode(HuffmanTree HT, HuffmanCode &HC, int n) {
    HC = new char*[n + 1];
    char *cd = new char[n + 1];
    cd[n] = '\0';
    for (int i = 1; i <= n; i++) {
        int start = n;
        int c = i, f = HT[i].parent;
        while (f != 0) {
            if (c == HT[f].lchild) cd[--start] = '0';
            else cd[--start] = '1';
            c = f;
            f = HT[c].parent;
        }
        HC[i] = new char[n - start + 1];
        strcpy(HC[i], &cd[start]);
    }
    delete[] cd;
}

int main() {
    HuffmanTree HT;
    HuffmanCode HC;
    int n, WPL = 0;
    cin >> n;
    if (n <= 1) {
        cout << "error" << endl;
        return 0;
    }
    createHuffmanTree(HT, n);
    createHuffmanCode(HT, HC, n);
    for (int i = 1; i <= n; i++) {
        cout << HT[i].weight << "编码为";
        cout << HC[i] << endl;
        WPL += strlen(HC[i]) * HT[i].weight;
    }
    cout << "WPL:" << WPL << endl;

    // 释放内存
    for (int i = 1; i <= n; i++) {
        delete[] HC[i];
    }
    delete[] HC;
    delete[] HT;
    return 0;
}