Update sk1/compressor.c
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2f587f253b
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461
sk1/compressor.c
461
sk1/compressor.c
@ -1,291 +1,250 @@
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#include "compressor.h"
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <string.h>
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#include <stdlib.h>
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// --- Алгоритм Run-Length Encoding (RLE) ---
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#define WINDOW_SIZE 4096
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#define LOOKAHEAD_BUFFER_SIZE 18
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int compress_2(const char* input_file_name, const char* output_file_name) {
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FILE *infile = fopen(input_file_name, "rb");
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if (!infile) {
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typedef struct {
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uint16_t offset;
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uint8_t length;
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uint8_t next_char;
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} LZ77Triple;
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int lz77_compress(const char *input_filename, const char *output_filename) {
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// Open the input file in binary read mode
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FILE *input_file = fopen(input_filename, "rb");
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if (!input_file) {
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perror("Error opening input file");
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return -1;
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}
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FILE *outfile = fopen(output_file_name, "wb");
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if (!outfile) {
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// Open the output file in binary write mode
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FILE *output_file = fopen(output_filename, "wb");
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if (!output_file) {
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perror("Error opening output file");
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fclose(infile);
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return -1;
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fclose(input_file);
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return -2;
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}
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unsigned char current_byte, previous_byte;
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size_t count = 0;
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if (fread(&previous_byte, 1, 1, infile) != 1) {
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fclose(infile);
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fclose(outfile);
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return 0; // Порожній файл
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uint8_t *window = (uint8_t *)malloc(WINDOW_SIZE + LOOKAHEAD_BUFFER_SIZE);
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if (!window) {
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perror("Memory allocation failed");
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fclose(input_file);
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fclose(output_file);
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return -3;
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}
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count = 1;
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size_t window_start = 0;
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size_t lookahead_start = 0;
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size_t bytes_read;
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while (fread(¤t_byte, 1, 1, infile) == 1) {
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// Initialize the window with data from the input file
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bytes_read = fread(window + WINDOW_SIZE, 1, LOOKAHEAD_BUFFER_SIZE, input_file);
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while (bytes_read > 0) {
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size_t best_match_offset = 0;
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size_t best_match_length = 0;
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// Search for the best match within the sliding window
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for (size_t i = window_start; i < WINDOW_SIZE + lookahead_start; i++) {
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size_t match_length = 0;
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while (match_length < bytes_read &&
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window[i + match_length] == window[WINDOW_SIZE + match_length]) {
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match_length++;
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if (match_length >= LOOKAHEAD_BUFFER_SIZE) {
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break;
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}
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}
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if (match_length > best_match_length) {
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best_match_length = match_length;
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best_match_offset = WINDOW_SIZE + lookahead_start - i;
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}
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}
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// Create a triple and write it to the output file
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LZ77Triple triple;
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triple.offset = (uint16_t)best_match_offset;
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triple.length = (uint8_t)best_match_length;
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triple.next_char = window[WINDOW_SIZE + best_match_length];
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// Write the triple to the output file
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fwrite(&triple, sizeof(LZ77Triple), 1, output_file);
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// Slide the window
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window_start = (window_start + best_match_length + 1) % WINDOW_SIZE;
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lookahead_start = (lookahead_start + best_match_length + 1) % LOOKAHEAD_BUFFER_SIZE;
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// Read new byte into the lookahead buffer
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bytes_read = fread(window + WINDOW_SIZE, 1, LOOKAHEAD_BUFFER_SIZE - lookahead_start, input_file);
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}
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// Cleanup and close files
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fclose(input_file);
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fclose(output_file);
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free(window);
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return 0;
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}
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int lz77_decompress(const char *input_filename, const char *output_filename) {
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FILE *input = fopen(input_filename, "rb");
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FILE *output = fopen(output_filename, "wb");
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if (!input || !output) {
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if (input) fclose(input);
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if (output) fclose(output);
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return -1; // Помилка відкриття файлу
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}
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size_t buffer_size = 4096; // Максимальний розмір вікна
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unsigned char *window = malloc(buffer_size);
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size_t window_size = 0; // Розмір заповненої частини вікна
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size_t window_pos = 0; // Поточна позиція в межах вікна
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if (!window) {
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fclose(input);
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fclose(output);
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return -1; // Помилка пам'яті
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}
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while (!feof(input)) {
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unsigned char flag;
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if (fread(&flag, 1, 1, input) != 1) break;
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for (int i = 0; i < 8 && !feof(input); i++) {
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if (flag & (1 << i)) { // Літеральний символ
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unsigned char literal;
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if (fread(&literal, 1, 1, input) != 1) break;
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fputc(literal, output);
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// Додати символ у вікно
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window[window_pos] = literal;
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window_pos = (window_pos + 1) % buffer_size;
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if (window_size < buffer_size) window_size++;
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} else { // Посилання
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unsigned short offset_length;
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if (fread(&offset_length, 2, 1, input) != 1) break;
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size_t offset = offset_length >> 4;
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size_t length = (offset_length & 0xF) + 3;
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for (size_t j = 0; j < length; j++) {
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unsigned char byte = window[(window_pos - offset + buffer_size) % buffer_size];
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fputc(byte, output);
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// Додати байт у вікно
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window[window_pos] = byte;
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window_pos = (window_pos + 1) % buffer_size;
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if (window_size < buffer_size) window_size++;
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}
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}
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}
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}
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free(window);
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fclose(input);
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fclose(output);
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return 0; // Успішна декомпресія
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}
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void rle_compress(const char *input_filename, const char *output_filename) {
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FILE *input_file = fopen(input_filename, "rb");
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if (!input_file) {
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perror("Error opening input file");
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return;
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}
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FILE *output_file = fopen(output_filename, "wb");
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if (!output_file) {
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perror("Error opening output file");
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fclose(input_file);
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return;
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}
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uint8_t current_byte, previous_byte;
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uint8_t count = 1;
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if (fread(&previous_byte, 1, 1, input_file) != 1) {
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printf("Input file is empty or read error occurred.\n");
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fclose(input_file);
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fclose(output_file);
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return;
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}
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while (fread(¤t_byte, 1, 1, input_file) == 1) {
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if (current_byte == previous_byte && count < 255) {
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count++;
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} else {
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fwrite(&previous_byte, 1, 1, outfile);
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fwrite(&count, 1, 1, outfile);
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fwrite(&previous_byte, 1, 1, output_file);
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fwrite(&count, 1, 1, output_file);
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printf("Writing byte: %c with count: %d\n", previous_byte, count);
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previous_byte = current_byte;
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count = 1;
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}
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}
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fwrite(&previous_byte, 1, 1, outfile);
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fwrite(&count, 1, 1, outfile);
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fwrite(&previous_byte, 1, 1, output_file);
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fwrite(&count, 1, 1, output_file);
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printf("Writing byte: %c with count: %d\n", previous_byte, count);
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fclose(infile);
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fclose(outfile);
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return 1;
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fclose(input_file);
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fclose(output_file);
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}
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int decompress_2(const char* input_file_name, const char* output_file_name) {
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FILE *infile = fopen(input_file_name, "rb");
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if (!infile) {
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int rle_decompress(const char *input_filename, const char *output_filename) {
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// Open the input file in binary read mode
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FILE *input_file = fopen(input_filename, "rb");
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if (!input_file) {
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perror("Error opening input file");
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return -1;
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}
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FILE *outfile = fopen(output_file_name, "wb");
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if (!outfile) {
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// Open the output file in binary write mode
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FILE *output_file = fopen(output_filename, "wb");
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if (!output_file) {
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perror("Error opening output file");
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fclose(infile);
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return -1;
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fclose(input_file);
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return -2;
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}
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unsigned char current_byte;
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unsigned char count;
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uint8_t byte;
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uint8_t count;
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size_t decompressed_size = 0;
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while (fread(¤t_byte, 1, 1, infile) == 1) {
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if (fread(&count, 1, 1, infile) != 1) {
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perror("Malformed input file");
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fclose(infile);
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fclose(outfile);
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return -1;
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// Read [byte, count] pairs from the input file
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while (fread(&byte, 1, 1, input_file) == 1) {
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if (fread(&count, 1, 1, input_file) != 1) {
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// Handle malformed input file
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fprintf(stderr, "Error: Malformed input file\n");
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fclose(input_file);
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fclose(output_file);
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return -3;
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}
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for (size_t i = 0; i < count; i++) {
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fwrite(¤t_byte, 1, 1, outfile);
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// Write 'count' occurrences of 'byte' to the output file
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for (uint8_t i = 0; i < count; i++) {
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if (fwrite(&byte, 1, 1, output_file) != 1) {
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perror("Error writing to output file");
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fclose(input_file);
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fclose(output_file);
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return -4;
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}
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decompressed_size++;
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}
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}
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fclose(infile);
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fclose(outfile);
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// Clean up and close files
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fclose(input_file);
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fclose(output_file);
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return 1;
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return (int)decompressed_size;
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}
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// --- Алгоритм Хаффмана (Huffman Coding) ---
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typedef struct Node {
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unsigned char symbol;
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size_t frequency;
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struct Node *left, *right;
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} Node;
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typedef struct {
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unsigned char symbol;
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char *code;
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} HuffmanCode;
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int compare_nodes(const void *a, const void *b) {
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return (*(Node**)a)->frequency - (*(Node**)b)->frequency;
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}
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Node* create_huffman_tree(unsigned char *data, size_t size) {
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size_t freq[256] = {0};
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for (size_t i = 0; i < size; i++) {
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freq[data[i]]++;
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}
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Node *nodes[256];
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size_t node_count = 0;
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for (int i = 0; i < 256; i++) {
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if (freq[i] > 0) {
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nodes[node_count] = malloc(sizeof(Node));
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if (!nodes[node_count]) {
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perror("Memory allocation failed");
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return NULL;
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}
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nodes[node_count]->symbol = (unsigned char)i;
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nodes[node_count]->frequency = freq[i];
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nodes[node_count]->left = nodes[node_count]->right = NULL;
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node_count++;
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}
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}
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while (node_count > 1) {
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qsort(nodes, node_count, sizeof(Node*), compare_nodes);
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Node* left = nodes[0];
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Node* right = nodes[1];
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Node* parent = malloc(sizeof(Node));
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if (!parent) {
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perror("Memory allocation failed");
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return NULL;
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}
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parent->symbol = 0;
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parent->frequency = left->frequency + right->frequency;
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parent->left = left;
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parent->right = right;
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memmove(nodes, nodes + 2, (node_count - 2) * sizeof(Node*));
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nodes[node_count - 2] = parent;
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node_count--;
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}
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return nodes[0];
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}
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void generate_huffman_codes(Node* root, HuffmanCode* codes, char* current_code, int depth) {
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if (!root) return;
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if (root->left == NULL && root->right == NULL) {
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current_code[depth] = '\0';
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codes[root->symbol].symbol = root->symbol;
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codes[root->symbol].code = strdup(current_code);
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return;
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}
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current_code[depth] = '0';
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generate_huffman_codes(root->left, codes, current_code, depth + 1);
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current_code[depth] = '1';
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generate_huffman_codes(root->right, codes, current_code, depth + 1);
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}
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void serialize_huffman_tree(Node* root, FILE* outfile) {
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if (!root) return;
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if (root->left == NULL && root->right == NULL) {
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fputc('L', outfile);
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fputc(root->symbol, outfile);
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} else {
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fputc('I', outfile);
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serialize_huffman_tree(root->left, outfile);
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serialize_huffman_tree(root->right, outfile);
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}
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}
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Node* rebuild_huffman_tree(unsigned char* tree_data, size_t size) {
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(void)size; // Позначаємо параметр як тимчасово невикористаний
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size_t index = 0;
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Node* build_tree_recursively(unsigned char* data, size_t* index) {
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if (data[*index] == 'L') { // Лист (Leaf)
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(*index)++;
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Node* leaf = malloc(sizeof(Node));
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if (!leaf) {
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perror("Memory allocation failed");
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return NULL;
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}
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leaf->symbol = data[*index];
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leaf->frequency = 0; // частота не потрібна для декомпресії
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leaf->left = leaf->right = NULL;
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(*index)++;
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return leaf;
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} else if (data[*index] == 'I') { // Вузол (Internal)
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(*index)++;
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Node* internal = malloc(sizeof(Node));
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if (!internal) {
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perror("Memory allocation failed");
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return NULL;
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}
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internal->symbol = 0; // внутрішні вузли не мають символів
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internal->frequency = 0;
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internal->left = build_tree_recursively(data, index);
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internal->right = build_tree_recursively(data, index);
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return internal;
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}
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return NULL;
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}
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return build_tree_recursively(tree_data, &index);
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}
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void free_huffman_tree(Node* root) {
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if (!root) return;
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free_huffman_tree(root->left);
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free_huffman_tree(root->right);
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free(root);
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}
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int compress_1(const char* input_file_name, const char* output_file_name) {
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FILE *infile = fopen(input_file_name, "rb");
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if (!infile) {
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perror("Error opening input file");
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return -1;
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}
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fseek(infile, 0, SEEK_END);
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size_t file_size = ftell(infile);
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fseek(infile, 0, SEEK_SET);
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unsigned char* data = malloc(file_size);
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if (!data) {
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fclose(infile);
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perror("Memory allocation failed");
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return -1;
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}
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fread(data, 1, file_size, infile);
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fclose(infile);
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Node* root = create_huffman_tree(data, file_size);
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if (!root) {
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free(data);
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return -1;
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}
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HuffmanCode codes[256] = {0};
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char current_code[256];
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generate_huffman_codes(root, codes, current_code, 0);
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FILE *outfile = fopen(output_file_name, "wb");
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if (!outfile) {
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free(data);
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free_huffman_tree(root);
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return -1;
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}
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serialize_huffman_tree(root, outfile);
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for (size_t i = 0; i < file_size; i++) {
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const char* code = codes[data[i]].code;
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for (size_t j = 0; code[j] != '\0'; j++) {
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fputc(code[j], outfile);
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}
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}
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fclose(outfile);
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free(data);
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free_huffman_tree(root);
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for (int i = 0; i < 256; i++) {
|
||||
free(codes[i].code);
|
||||
}
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
// Декомпресія (приклад потребує уточнень залежно від специфіки формату)
|
||||
int decompress_1(const char* input_file_name, const char* output_file_name) {
|
||||
(void)input_file_name;
|
||||
(void)output_file_name;
|
||||
return -1; // Поки що не реалізовано.
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user