Merge pull request #543 from aditmehta9/patch-2

Huffman code in C++

huffmancode.cpp

@@ -0,0 +1,86 @@
+#include <bits/stdc++.h> 
+using namespace std; 
+
+struct MinHeapNode { 
+
+    char data; 
+
+    unsigned freq; 
+
+    MinHeapNode *left, *right; 
+
+    MinHeapNode(char data, unsigned freq) 
+
+    { 
+
+        left = right = NULL; 
+        this->data = data; 
+        this->freq = freq; 
+    } 
+}; 
+
+
+struct compare { 
+
+    bool operator()(MinHeapNode* l, MinHeapNode* r) 
+
+    { 
+        return (l->freq > r->freq); 
+    } 
+}; 
+
+void printCodes(struct MinHeapNode* root, string str) 
+{ 
+
+    if (!root) 
+        return; 
+
+    if (root->data != '$') 
+        cout << root->data << ": " << str << "\n"; 
+
+    printCodes(root->left, str + "0"); 
+    printCodes(root->right, str + "1"); 
+} 
+
+void HuffmanCodes(char data[], int freq[], int size) 
+{ 
+    struct MinHeapNode *left, *right, *top; 
+
+    // Create a min heap & inserts all characters of data[] 
+    priority_queue<MinHeapNode*, vector<MinHeapNode*>, compare> minHeap; 
+
+    for (int i = 0; i < size; ++i) 
+        minHeap.push(new MinHeapNode(data[i], freq[i])); 
+
+    while (minHeap.size() != 1) { 
+
+
+        left = minHeap.top(); 
+        minHeap.pop(); 
+
+        right = minHeap.top(); 
+        minHeap.pop(); 
+
+        top = new MinHeapNode('$', left->freq + right->freq); 
+
+        top->left = left; 
+        top->right = right; 
+
+        minHeap.push(top); 
+    } 
+
+    printCodes(minHeap.top(), ""); 
+} 
+
+int main() 
+{ 
+
+    char arr[] = { 'a', 'b', 'c', 'd', 'e', 'f' }; 
+    int freq[] = { 5, 9, 12, 13, 16, 45 }; 
+
+    int size = sizeof(arr) / sizeof(arr[0]); 
+
+    HuffmanCodes(arr, freq, size); 
+
+    return 0; 
+}