From 81561e6a74710233553a2cc8c91d2623ec9a85a7 Mon Sep 17 00:00:00 2001
From: yashmunoth <yash.munoth@gmail.com>
Date: Mon, 15 Oct 2018 23:04:45 +0530
Subject: [PATCH 1/2] Program for Huffman Coding in C++

---
 Greedy Algorithms/huffman.cpp | 108 ++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 Greedy Algorithms/huffman.cpp

diff --git a/Greedy Algorithms/huffman.cpp b/Greedy Algorithms/huffman.cpp
new file mode 100644
index 000000000..be3ed4880
--- /dev/null
+++ b/Greedy Algorithms/huffman.cpp	
@@ -0,0 +1,108 @@
+// C++ program for Huffman Coding 
+#include <bits/stdc++.h> 
+using namespace std; 
+  
+// A Huffman tree node 
+struct MinHeapNode { 
+  
+    // One of the input characters 
+    char data; 
+  
+    // Frequency of the character 
+    unsigned freq; 
+  
+    // Left and right child 
+    MinHeapNode *left, *right; 
+  
+    MinHeapNode(char data, unsigned freq) 
+  
+    { 
+  
+        left = right = NULL; 
+        this->data = data; 
+        this->freq = freq; 
+    } 
+}; 
+  
+// For comparison of 
+// two heap nodes (needed in min heap) 
+struct compare { 
+  
+    bool operator()(MinHeapNode* l, MinHeapNode* r) 
+  
+    { 
+        return (l->freq > r->freq); 
+    } 
+}; 
+  
+// Prints huffman codes from 
+// the root of Huffman Tree. 
+void printCodes(struct MinHeapNode* root, string str) 
+{ 
+  
+    if (!root) 
+        return; 
+  
+    if (root->data != '$') 
+        cout << root->data << ": " << str << "\n"; 
+  
+    printCodes(root->left, str + "0"); 
+    printCodes(root->right, str + "1"); 
+} 
+  
+// The main function that builds a Huffman Tree and 
+// print codes by traversing the built Huffman Tree 
+void HuffmanCodes(char data[], int freq[], int size) 
+{ 
+    struct MinHeapNode *left, *right, *top; 
+  
+    // Create a min heap & inserts all characters of data[] 
+    priority_queue<MinHeapNode*, vector<MinHeapNode*>, compare> minHeap; 
+  
+    for (int i = 0; i < size; ++i) 
+        minHeap.push(new MinHeapNode(data[i], freq[i])); 
+  
+    // Iterate while size of heap doesn't become 1 
+    while (minHeap.size() != 1) { 
+  
+        // Extract the two minimum 
+        // freq items from min heap 
+        left = minHeap.top(); 
+        minHeap.pop(); 
+  
+        right = minHeap.top(); 
+        minHeap.pop(); 
+  
+        // Create a new internal node with 
+        // frequency equal to the sum of the 
+        // two nodes frequencies. Make the 
+        // two extracted node as left and right children 
+        // of this new node. Add this node 
+        // to the min heap '$' is a special value 
+        // for internal nodes, not used 
+        top = new MinHeapNode('$', left->freq + right->freq); 
+  
+        top->left = left; 
+        top->right = right; 
+  
+        minHeap.push(top); 
+    } 
+  
+    // Print Huffman codes using 
+    // the Huffman tree built above 
+    printCodes(minHeap.top(), ""); 
+} 
+  
+// Driver program to test above functions 
+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; 
+} 

From 85c3d5aaad5e5f691b28b3a663501a9199ee7217 Mon Sep 17 00:00:00 2001
From: Ashwek Swamy <39827514+ashwek@users.noreply.github.com>
Date: Sun, 10 Nov 2019 19:02:54 +0530
Subject: [PATCH 2/2] change header files

---
 Greedy Algorithms/huffman.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Greedy Algorithms/huffman.cpp b/Greedy Algorithms/huffman.cpp
index be3ed4880..253d8d0b5 100644
--- a/Greedy Algorithms/huffman.cpp	
+++ b/Greedy Algorithms/huffman.cpp	
@@ -1,5 +1,6 @@
 // C++ program for Huffman Coding 
-#include <bits/stdc++.h> 
+#include <iostream>
+#include <queue> 
 using namespace std; 
   
 // A Huffman tree node