#include <iostream>
#include <cstdlib>
using namespace std;
#define MAX_TREE_HT 100
struct MinHeapNode {
char data;
unsigned freq;
struct MinHeapNode *left, *right;
};
struct MinHeap {
unsigned size;
unsigned capacity;
struct MinHeapNode** array;
};
struct MinHeapNode* newNode(char data, unsigned freq)
{
struct MinHeapNode* temp
= (struct MinHeapNode*)malloc
(sizeof(struct MinHeapNode));
temp->left = temp->right = NULL;
temp->data = data;
temp->freq = freq;
return temp;
}
struct MinHeap* createMinHeap(unsigned capacity)
{
struct MinHeap* minHeap
= (struct MinHeap*)malloc(sizeof(struct MinHeap));
minHeap->size = 0;
minHeap->capacity = capacity;
minHeap->array
= (struct MinHeapNode**)malloc(minHeap->
capacity * sizeof(struct MinHeapNode*));
return minHeap;
}
void swapMinHeapNode(struct MinHeapNode** a,
struct MinHeapNode** b)
{
struct MinHeapNode* t = *a;
*a = *b;
*b = t;
}
void minHeapify(struct MinHeap* 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) {
swapMinHeapNode(&minHeap->array[smallest],
&minHeap->array[idx]);
minHeapify(minHeap, smallest);
}
}
int isSizeOne(struct MinHeap* minHeap)
{
return (minHeap->size == 1);
}
struct MinHeapNode* extractMin(struct MinHeap* minHeap)
{
struct MinHeapNode* temp = minHeap->array[0];
minHeap->array[0]
= minHeap->array[minHeap->size - 1];
--minHeap->size;
minHeapify(minHeap, 0);
return temp;
}
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;
}
minHeap->array[i] = minHeapNode;
}
void buildMinHeap(struct MinHeap* minHeap)
{
int n = minHeap->size - 1;
int i;
for (i = (n - 1) / 2; i >= 0; --i)
minHeapify(minHeap, i);
}
void printArr(int arr[], int n)
{
int i;
for (i = 0; i < n; ++i)
cout<< arr[i];
cout<<"\n";
}
int isLeaf(struct MinHeapNode* root)
{
return !(root->left) && !(root->right);
}
struct MinHeap* createAndBuildMinHeap(char data[], int freq[], int size)
{
struct MinHeap* minHeap = createMinHeap(size);
for (int i = 0; i < size; ++i)
minHeap->array[i] = newNode(data[i], freq[i]);
minHeap->size = size;
buildMinHeap(minHeap);
return minHeap;
}
struct MinHeapNode* buildHuffmanTree(char data[], int freq[], int size)
{
struct MinHeapNode *left, *right, *top;
struct MinHeap* minHeap = createAndBuildMinHeap(data, freq, size);
while (!isSizeOne(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 printCodes(struct MinHeapNode* root, int arr[], int top)
{
if (root->left)
{
arr[top] = 0;
printCodes(root->left, arr, top + 1);
}
if (root->right)
{
arr[top] = 1;
printCodes(root->right, arr, top + 1);
}
if (isLeaf(root)) {
cout<< root->data <<": ";
printArr(arr, top);
}
}
void HuffmanCodes(char data[], int freq[], int size)
{
struct MinHeapNode* root = buildHuffmanTree(data, freq, size);
int arr[MAX_TREE_HT], top = 0;
printCodes(root, arr, 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;
}
Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!
OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.
#include <iostream>
#include <string>
using namespace std;
int main()
{
string name;
cout << "Enter name:";
getline (cin, name);
cout << "Hello " << name;
return 0;
}
C++ is a widely used middle-level programming language.
When ever you want to perform a set of operations based on a condition If-Else is used.
if(conditional-expression) {
//code
}
else {
//code
}
You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.
Switch is an alternative to If-Else-If ladder.
switch(conditional-expression){
case value1:
// code
break; // optional
case value2:
// code
break; // optional
......
default:
code to be executed when all the above cases are not matched;
}
For loop is used to iterate a set of statements based on a condition.
for(Initialization; Condition; Increment/decrement){
//code
}
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while (condition) {
// code
}
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (condition);
Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.
return_type function_name(parameters);
function_name (parameters)
return_type function_name(parameters) {
// code
}