LZW算法在C++中实现

LZW算法是一种用于数据压缩的算法，下面是一个简单的C语言实现：

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

#define TABLE_SIZE 4096

void compress(char *uncompressed, FILE *output) {
    int i;
    int dict_size = 256;
    int *dict = (int*)malloc(TABLE_SIZE * sizeof(int));
    for (i = 0; i < 256; i++) {
        dict[i] = i;
    }

    int len = strlen(uncompressed);
    int p = 0;
    int c = 0;
    while (p < len) {
        c = uncompressed[p++];
        while (p < len && dict[c] != -1) {
            c = (c << 8) + uncompressed[p++];
        }
        if (dict[c] == -1) {
            dict[c] = dict_size++;
            if (dict_size > TABLE_SIZE) {
                printf("Error: table size exceeded\n");
                exit(1);
            }
            fwrite(&dict[c >> 8], 2, 1, output);
            fwrite(&dict[c & 0xFF], 1, 1, output);
        }
        c = uncompressed[p - 1];
    }
    fwrite(&dict[c >> 8], 2, 1, output);
    fwrite(&dict[c & 0xFF], 1, 1, output);

    free(dict);
}

void decompress(FILE *input, char *decompressed) {
    int i;
    int dict_size = 256;
    int *dict = (int*)malloc(TABLE_SIZE * sizeof(int));
    for (i = 0; i < 256; i++) {
        dict[i] = i;
    }

    int p = 0;
    int c = 0;
    int prev = -1;
    while (1) {
        int hi = fgetc(input);
        int lo = fgetc(input);
        if (hi == EOF || lo == EOF) {
            break;
        }
        c = (hi << 8) + lo;
        if (c >= dict_size) {
            printf("Error: bad compressed data\n");
            exit(1);
        }
        if (prev != -1) {
            dict[dict_size++] = dict[prev] + (char)(dict[c] & 0xFF);
            memcpy(decompressed + p, dict + prev, dict[c] + 1);
            p += dict[c] + 1;
        } else {
            memcpy(decompressed + p, dict + c, 1);
            p += 1;
        }
        prev = c;
    }

    free(dict);
}

int main() {
    char uncompressed[] = "TOBEORNOTTOBEORTOBEORNOT#";
    FILE *output = fopen("compressed", "wb");
    compress(uncompressed, output);
    fclose(output);

    char *decompressed = (char*)malloc(strlen(uncompressed) + 1);
    FILE *input = fopen("compressed", "rb");
    decompress(input, decompressed);
    fclose(input);

    if (strcmp(uncompressed, decompressed) == 0) {
        printf("Compression/decompression successful\n");
    } else {
        printf("Compression/decompression failed\n");
    }
    free(decompressed);

    return 0;
}

上面的代码包括了LZW算法的压缩和解压缩过程。在压缩过程中，算法将输入的字符串转换为整数，并将整数输出到文件中。在解压缩过程中，算法从文件中读取整数，并将整数转换为输出字符串。注意，这个实现是用于处理文本字符串的，如果需要处理二进制数据，需要进行一些修改。