Обновить sk1/compressor.c

sk1/compressor.c

@@ -4,76 +4,46 @@
 
 #define MAX_TREE_HT 256
 
-// Узел дерева Хаффмана
+// A Huffman tree node
 struct MinHeapNode {
     unsigned char data;
     unsigned freq;
     struct MinHeapNode *left, *right;
 };
 
-// Минкуча
+// A MinHeap
 struct MinHeap {
     unsigned size;
     unsigned capacity;
     struct MinHeapNode** array;
 };
 
-// Функция для создания нового узла
+// Function to create a new node
 struct MinHeapNode* createNode(unsigned char data, unsigned freq) {
     struct MinHeapNode* temp = (struct MinHeapNode*)malloc(sizeof(struct MinHeapNode));
-    if (!temp) {
-        perror("Ошибка выделения памяти для узла дерева");
-        exit(EXIT_FAILURE);
-    }
     temp->data = data;
     temp->freq = freq;
     temp->left = temp->right = NULL;
     return temp;
 }
 
-// Функция для создания Минкучи
+// Function to create a MinHeap
 struct MinHeap* createMinHeap(unsigned capacity) {
     struct MinHeap* minHeap = (struct MinHeap*)malloc(sizeof(struct MinHeap));
-    if (!minHeap) {
-        perror("Ошибка выделения памяти для Минкучи");
-        exit(EXIT_FAILURE);
-    }
     minHeap->size = 0;
     minHeap->capacity = capacity;
     minHeap->array = (struct MinHeapNode**)malloc(minHeap->capacity * sizeof(struct MinHeapNode*));
-    if (!minHeap->array) {
-        perror("Ошибка выделения памяти для массива Минкучи");
-        free(minHeap);
-        exit(EXIT_FAILURE);
-    }
     return minHeap;
 }
 
-// Функция для освобождения памяти дерева
-void freeHuffmanTree(struct MinHeapNode* root) {
-    if (!root) return;
-    freeHuffmanTree(root->left);
-    freeHuffmanTree(root->right);
-    free(root);
-}
-
-// Освобождение памяти массива кодов
-void freeCodes(char** codes) {
-    for (int i = 0; i < 256; i++) {
-        if (codes[i]) {
-            free(codes[i]);
-        }
-    }
-}
-
-// Swap
+// Swap function
 void swapMinHeapNode(struct MinHeapNode** a, struct MinHeapNode** b) {
     struct MinHeapNode* t = *a;
     *a = *b;
     *b = t;
 }
 
-// MinHeapify
+// MinHeapify function
 void minHeapify(struct MinHeap* minHeap, int idx) {
     int smallest = idx;
     int left = 2 * idx + 1;
@@ -91,7 +61,7 @@ void minHeapify(struct MinHeap* minHeap, int idx) {
     }
 }
 
-// Извлечение минимального узла
+// Extract minimum value node from heap
 struct MinHeapNode* extractMin(struct MinHeap* minHeap) {
     struct MinHeapNode* temp = minHeap->array[0];
     minHeap->array[0] = minHeap->array[minHeap->size - 1];
@@ -100,11 +70,10 @@ struct MinHeapNode* extractMin(struct MinHeap* minHeap) {
     return temp;
 }
 
-// Вставка нового узла в Минкучу
+// Insert a new node to MinHeap
 void insertMinHeap(struct MinHeap* minHeap, struct MinHeapNode* minHeapNode) {
     ++minHeap->size;
     int i = minHeap->size - 1;
-
     while (i && minHeapNode->freq < minHeap->array[(i - 1) / 2]->freq) {
         minHeap->array[i] = minHeap->array[(i - 1) / 2];
         i = (i - 1) / 2;
@@ -112,39 +81,47 @@ void insertMinHeap(struct MinHeap* minHeap, struct MinHeapNode* minHeapNode) {
     minHeap->array[i] = minHeapNode;
 }
 
-// Создание и построение Минкучи
+// Build the MinHeap
+void buildMinHeap(struct MinHeap* minHeap) {
+    int n = minHeap->size - 1;
+    for (int i = (n - 1) / 2; i >= 0; --i)
+        minHeapify(minHeap, i);
+}
+
+// Check if size is 1
+int isSizeOne(struct MinHeap* minHeap) {
+    return (minHeap->size == 1);
+}
+
+// Create and build a MinHeap
 struct MinHeap* createAndBuildMinHeap(unsigned char data[], int freq[], int size) {
     struct MinHeap* minHeap = createMinHeap(size);
     for (int i = 0; i < size; ++i)
         minHeap->array[i] = createNode(data[i], freq[i]);
     minHeap->size = size;
-    for (int i = (minHeap->size - 2) / 2; i >= 0; --i)
-        minHeapify(minHeap, i);
+    buildMinHeap(minHeap);
     return minHeap;
 }
 
-// Построение дерева Хаффмана
+// Build Huffman Tree
 struct MinHeapNode* buildHuffmanTree(unsigned char data[], int freq[], int size) {
     struct MinHeapNode *left, *right, *top;
     struct MinHeap* minHeap = createAndBuildMinHeap(data, freq, size);
 
-    while (minHeap->size > 1) {
+    while (!isSizeOne(minHeap)) {
         left = extractMin(minHeap);
         right = extractMin(minHeap);
 
         top = createNode('$', left->freq + right->freq);
         top->left = left;
         top->right = right;
+
         insertMinHeap(minHeap, top);
     }
-
-    struct MinHeapNode* root = extractMin(minHeap);
-    free(minHeap->array);
-    free(minHeap);
-    return root;
+    return extractMin(minHeap);
 }
 
-// Сохранение кодов
+// Print Huffman Codes to a map
 void storeCodes(struct MinHeapNode* root, char** codes, char* currentCode, int top) {
     if (root->left) {
         currentCode[top] = '0';
@@ -157,13 +134,8 @@ void storeCodes(struct MinHeapNode* root, char** codes, char* currentCode, int t
     if (!(root->left) && !(root->right)) {
         currentCode[top] = '\0';
         codes[root->data] = strdup(currentCode);
-        if (!codes[root->data]) {
-            perror("Ошибка выделения памяти для кодов");
-            exit(EXIT_FAILURE);
     }
 }
-}
-
 
 // Compress the input file using Huffman Coding
 int compressFile(const char* input_file_name, const char* output_file_name) {
@@ -225,7 +197,7 @@ int compressFile(const char* input_file_name, const char* output_file_name) {
         byte <<= (8 - bitCount);
         fwrite(&byte, sizeof(unsigned char), 1, outputFile);
     }
-    freeHuffmanTree(root);
+
     fclose(inputFile);
     fclose(outputFile);
     return 0;
@@ -278,7 +250,7 @@ int decompressFile(const char* input_file_name, const char* output_file_name) {
             }
         }
     }
-    freeHuffmanTree(root);
+
     fclose(inputFile);
     fclose(outputFile);
     return 0;