diff --git a/hauffman_Coding.cpp b/hauffman_Coding.cpp new file mode 100644 index 0000000..7c72d43 --- /dev/null +++ b/hauffman_Coding.cpp @@ -0,0 +1,170 @@ +#include +using namespace std; + +#define MAX_TREE_HT 50 + +struct MinHNode { + unsigned freq; + char item; + struct MinHNode *left, *right; +}; + +struct MinH { + unsigned size; + unsigned capacity; + struct MinHNode **array; +}; + +struct MinHNode *newNode(char item, unsigned freq) { + struct MinHNode *temp = (struct MinHNode *)malloc(sizeof(struct MinHNode)); + + temp->left = temp->right = NULL; + temp->item = item; + temp->freq = freq; + + return temp; +} + +struct MinH *createMinH(unsigned capacity) { + struct MinH *minHeap = (struct MinH *)malloc(sizeof(struct MinH)); + minHeap->size = 0; + minHeap->capacity = capacity; + minHeap->array = (struct MinHNode **)malloc(minHeap->capacity * sizeof(struct MinHNode *)); + return minHeap; +} +void printArray(int arr[], int n) { + int i; + for (i = 0; i < n; ++i) + cout << arr[i]; + + cout << "\n"; +} + +void swapMinHNode(struct MinHNode **a, struct MinHNode **b) { + struct MinHNode *t = *a; + *a = *b; + *b = t; +} + +void minHeapify(struct MinH *minHeap, int idx) { + int smallest = idx; + int left = 2 * idx + 1; + int right = 2 * idx + 2; + + if (left < minHeap->size && minHeap->array[left]->freq < minHeap->array[smallest]->freq) + smallest = left; + + if (right < minHeap->size && minHeap->array[right]->freq < minHeap->array[smallest]->freq) + smallest = right; + + if (smallest != idx) { + swapMinHNode(&minHeap->array[smallest], + &minHeap->array[idx]); + minHeapify(minHeap, smallest); + } +} + +int checkSizeOne(struct MinH *minHeap) { + return (minHeap->size == 1); +} + + +struct MinHNode *extractMin(struct MinH *minHeap) { + struct MinHNode *temp = minHeap->array[0]; + minHeap->array[0] = minHeap->array[minHeap->size - 1]; + + --minHeap->size; + minHeapify(minHeap, 0); + + return temp; +} + +void insertMinHeap(struct MinH *minHeap, struct MinHNode *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; + } + + minHeap->array[i] = minHeapNode; +} + + +void buildMinHeap(struct MinH *minHeap) { + int n = minHeap->size - 1; + int i; + + for (i = (n - 1) / 2; i >= 0; --i) + minHeapify(minHeap, i); +} + +int isLeaf(struct MinHNode *root) { + return !(root->left) && !(root->right); +} + +struct MinH *createAndBuildMinHeap(char item[], int freq[], int size) { + struct MinH *minHeap = createMinH(size); + + for (int i = 0; i < size; ++i) + minHeap->array[i] = newNode(item[i], freq[i]); + + minHeap->size = size; + buildMinHeap(minHeap); + + return minHeap; +} + +struct MinHNode *buildHfTree(char item[], int freq[], int size) { + struct MinHNode *left, *right, *top; + struct MinH *minHeap = createAndBuildMinHeap(item, freq, size); + + while (!checkSizeOne(minHeap)) { + left = extractMin(minHeap); + right = extractMin(minHeap); + + top = newNode('$', left->freq + right->freq); + + top->left = left; + top->right = right; + + insertMinHeap(minHeap, top); + } + return extractMin(minHeap); +} +void printHCodes(struct MinHNode *root, int arr[], int top) { + if (root->left) { + arr[top] = 0; + printHCodes(root->left, arr, top + 1); + } + + if (root->right) { + arr[top] = 1; + printHCodes(root->right, arr, top + 1); + } + if (isLeaf(root)) { + cout << root->item << " | "; + printArray(arr, top); + } +} + + +void HuffmanCodes(char item[], int freq[], int size) { + struct MinHNode *root = buildHfTree(item, freq, size); + + int arr[MAX_TREE_HT], top = 0; + + printHCodes(root, arr, top); +} + +int main() { + char arr[] = {'A', 'B', 'C', 'D'}; + int freq[] = {5, 1, 6, 3}; + + int size = sizeof(arr) / sizeof(arr[0]); + + cout << "Char | Huffman code "; + cout << "\n--------------------\n"; + HuffmanCodes(arr, freq, size); +}