给出文件中题目：给定五个字符a~f，它们的权值集W={2,3,4,7,8,9}，试构造关于W的一棵哈夫曼树，求其带权路径长度WPL和各个字符的哈夫曼编码。的具体c语言代码

基于您的需求，以下是针对给定问题的具体C语言代码实现，用于构造哈夫曼树，求其带权路径长度WPL以及每个字符对应的哈夫曼编码：

### 定义数据结构

首先定义节点和哈夫曼编码的结构体：

#include <stdio.h>
#include <stdlib.h>

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

typedef struct {
    unsigned char bit[10];
    int start;
} HCode, *HCoding;

### 构造哈夫曼树

构造哈夫曼树的函数 `CreateHuffmanTree`:

void CreateHuffmanTree(HuffmanTree *ht, int *w, int n) {
    if(n <= 1)
        return;

    HuffmanTree huffman = (HuffmanTree)malloc((n*2+1)*sizeof(HTNode));
    for(int i = 0; i <= n*2; ++i) {
        huffman[i].parent = huffman[i].lchild = huffman[i].rchild = -1;
    }

    for(int i = 1; i <= n; ++i)
        huffman[i].weight = w[i-1];

    int m = 2*n - 1;
    for(int i = n + 1; i <= m; ++i) {
        int s1 = -1, s2 = -1, min1, min2;
        for(int j = 1; j <= i - 1; ++j) {
            if(huffman[j].weight > 0 && huffman[j].parent == -1) {
                if(s1 == -1 || huffman[j].weight < min1) {
                    s2 = s1;
                    min2 = min1;
                    s1 = j;
                    min1 = huffman[j].weight;
                } else if(s2 == -1 || huffman[j].weight < min2) {
                    s2 = j;
                    min2 = huffman[j].weight;
                }
            }
        }

        huffman[s1].parent = huffman[s2].parent = i;
        huffman[s2].lchild = s2;
        huffman[s1].rchild = s1;
        huffman[i].weight = huffman[s1].weight + huffman[s2].weight;
    }

    *ht = huffman;
}

### 生成哈夫曼编码

生成哈夫曼编码的函数 `GenerateHuffmaanCodes`:

void GenerateHuffmaanCodes(HuffmanTree ht, int n, HCoding cd) {
    int start;
    cd = (HCoding)malloc((n+1)*sizeof(HCode));

    for(int i = 1; i <= n; ++i) {
        start = 10; /* 从bit[1]开始存储，从第10位倒回至1位 */
        for(int c = i, f = ht[i].parent; f != -1; c=f, f=ht[f].parent) {
            if(ht[f].lchild == c) 
                cd[i].bit[--start] = '0';  
            else 
                cd[i].bit[--start] = '1';
        }
        cd[i].start = start;
    }
}

### 打印哈夫曼编码

打印哈夫曼编码的函数 `PrintHuffmaanCodes`:

void PrintHuffmaanCodes(HCoding cd, int *ch, int n) {
    int WPL = 0;

    printf("Huffman Coding: \n");
    for(int i = 1; i <= n; ++i) {
        printf("%c: ", ch[i-1]);
        for(int j = cd[i].start; j <= 10; ++j) {
            printf("%c", cd[i].bit[j]);
            WPL += ('0' == cd[i].bit[j]) ? 0 : ht[i].weight; 
        }
        printf("\n");
    }

    printf("Weighted Path Length (WPL): %d\n", WPL);
}

### 主函数

整合以上所有部分，形成完整程序：

int main() {
    int weights[] = {2, 3, 4, 7, 8, 9};
    char chars[] = {'a', 'b', 'c', 'd', 'e', 'f'};
    int n = sizeof(weights) / sizeof(int);

    HuffmanTree ht = NULL;
    HCoding hc = NULL;

    CreateHuffmanTree(&ht, weights, n);
    GenerateHuffmaanCodes(ht, n, hc);
    PrintHuffmaanCodes(hc, chars, n);

    free(ht); 
    free(hc);

    return 0;
}

此程序段能够构造给定重量集下的哈夫曼树，并生成每个字符对应的编码及计算WPL。注意内存的合理分配与释放以保证没有内存泄漏的问题出现。