i am writing a program on huffman's code in C++.
I have wriiten the program till building the huffman tree. now I have to generate the code by traversing the huffman tree. I have no idea how to do that logically. please help with code or algorithm.
Here is my code so far.
IDE used is dev-cpp.

#include<iostream>
#include<stdio.h>
#include<fstream>
using namespace std;

#define MAX_SYM 256

class node;
//GLOBAL VARIABLES
node *queue_top;
int heap_size;

class node
{
      int freq;
      char ch;
      node *left, *right;
      node* next;
      
      public:
      node()
      {
            left = NULL;
            right= NULL;
            next= NULL;
      }
      void ini(int i)
      {
           freq=i;
      }
      void display()
      {
           cout<<"node is: "<<ch<<endl;
           cout<<"Freq is: "<<freq<<endl;
      }
      void extract_min_node()
      {
            freq= queue_top->freq;                  //copying
            ch= queue_top->ch;
            next=NULL;                              //no need to copy left,right as they contain NULL
            queue_top=queue_top->next;
            heap_size--;
      }
      int get_freq()
      {
          return freq;
      }
      friend void gen_freq(char *);
      friend void insert_queue(node *);
      friend void build_huffman();
      
}PQ[MAX_SYM];

----------------------------------------------CLASS DECLARATION OVER----------------------------------------------------------------

void gen_freq(char *file_name)
{
      ifstream fin;
      fin.open(file_name,ios::in);
      char ch;
      fin>>ch;
      while (fin)
      {
            PQ[int(ch)].freq++;
      }
}
void insert_queue(node* x)
     {
     int flag=0;
     node *smallest,*temp;
     if (heap_size==0)
        queue_top=x;
     else
     {
         if (x->freq < PQ[0].freq)
         {
                 //put node at start of the queue
                 temp=queue_top;
                 queue_top=x;
                 x->next=temp;  
         }
         int i=1;
         while (i<heap_size)
         {
                 if (x->freq < PQ[i].freq) 
                 {
                    x->next=&PQ[i];
                    PQ[i-1].next=x;
                    flag = 1;
                    break;
                 }
                 
         }
         if (flag==0)
         {
            PQ[heap_size-1].next=x;
         } 
     }
     heap_size++;
}

void build_huffman()
{
     node l,r,newt;
     for(int i=0;i<(heap_size-1);i++)                  //in heapsize-1 iterations only 1 root node will be left
     {
             l.extract_min_node();
             r.extract_min_node();
             newt.freq= l.freq+r.freq;
             newt.left=&l;
             newt.right=&r;
             insert_queue(&newt);
     }
}
void generate_code(char [])
{
}
void encode()
{
}

int main()
{
    //initialize the queue
    for (int i= 0; i<256; i++)
    {
        PQ[i].ini(i); 
    }
    
    //input text file name
    char file_name[100];
    cout<<"Enter name of text file: ";
    gets(file_name);
    
    //create frequencies from file
    gen_freq(file_name);
    for (int i= 0; i<256; i++)
    {
        PQ[i].display(); 
    }
    for (int i= 0; i<256; i++)            // insert node for a EXISTING symbol
    {
        if (PQ[i].get_freq()!=0)
        insert_queue(&PQ[i]); 
    }
    //build huffman tree
    build_huffman();
    
    //create code for each symbol
    char a[MAX_SYM];
    generate_code(a);
    
    //encode the given file
    encode();
    
    system("pause");
    return 0;
}

Ok i was able to do generate the code using recursive function calls.

Now I am having a problem that 'Dev-CPP IDE' shows an error "dev-cpp has stopped working" when i run the program. The program executes fine though.

Ok the problem is resolved for now. I will ask mods for deleting this thread as the code given by me here is not good and there haven't been any replies also. The thread isn't worth saving.