Sixteen-Algorithm-Problems/HUFFMAN CODING.cpp at master · fesabelilla/Sixteen-Algorithm-Problems · GitHub

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#include<bits/stdc++.h>
using namespace std;

struct node
{
    node * leftChild;
    node * rightChild;
    double frequency;
    string content;
    string code;

};

vector<node> nodeArray;// Use nodeArray to record all the nodes that may be created in the whole process

node  extractMin()
{
    double temp = (double) INT_MAX;
    vector<node>::iterator i1,pos;
    for(i1 = nodeArray.begin(); i1!=nodeArray.end(); i1++)
    {

        if(temp>(*i1).frequency)
        {
            pos = i1;
            temp = (*i1).frequency;
        }
    }

    node tempNode = (*pos);
    nodeArray.erase(pos);


    return tempNode;
}


node getHuffmanTree()
{

    while(!nodeArray.empty())
    {


        node * tempNode = new node;
        node * tempNode1 = new node;
        node * tempNode2 = new node;
        *tempNode1 = extractMin();
        *tempNode2 = extractMin();


        tempNode->leftChild = tempNode1;
        tempNode->rightChild = tempNode2;
        tempNode->frequency = tempNode1->frequency+tempNode2->frequency;
        nodeArray.push_back(*tempNode);
        if(nodeArray.size() == 1)//only the root node exsits
        {
            break;
        }
    }
    return nodeArray[0];
}


void BFS(node * temproot,string s)
{
    node * root1 = new node;
    root1 = temproot;

    root1->code = s;
    if(root1 == NULL)
    {

    }
    else if(root1->leftChild == NULL && root1->rightChild == NULL)
    {

        cout<<"the content is "<<root1->content<<endl;
        cout<<"and its corresponding code is "<<root1->code<<endl;
    }
    else
    {

        root1->leftChild->code = s.append("0");
        s.erase(s.end()-1);
        root1->rightChild->code = s.append("1");
        s.erase(s.end()-1);


        BFS(root1->leftChild,s.append("0"));
        s.erase(s.end()-1);
        BFS(root1->rightChild,s.append("1"));
        s.erase(s.end()-1);
    }

}


void getHuffmanCode()
{
    int size,i;
    double tempDouble;
    string tempString = "";

    cout<<"please input the number of things you want to encode!"<<endl;
    cin>>size;

    for(i = 0; i<size; i++)
    {
        cout<<"please input the things you want to encoded and their frequencies!"<<endl;
        node tempNode;
        cin>>tempString;
        cin>>tempDouble;


        tempNode.frequency = tempDouble;
        tempNode.content = tempString;
        tempNode.leftChild = NULL;
        tempNode.rightChild = NULL;
        nodeArray.push_back(tempNode);
    }


    node root = getHuffmanTree();


    BFS(&root,"");

}


int main()
{
    int n;
    vector<int> test;
    cin>>n;
    for(int i=0; i<n; i++)
    {
        int a;
        cin>>a;
        test.push_back(a);
    }
    vector<int>::iterator i1 = test.begin();
    test.erase(i1);

    getHuffmanCode();
    return 0;
}