c++ - undefined reference to CLASS::function() -

so when try compile code using "g++ asg5.cpp" receive following error

/tmp/cczhpsgo.o: in function 'main':

asg5.cpp:(.text+0x2fb): undefined reference 'binomialtree::insert(int)'

collect2: ld returned 1 exit status

if anyone's wondering why i'm not using makefile, professor wants type g++ <.cpp main()> compile..

anyway here's code appreciate assistance!

asg5.cpp

#include "binomialtree.h" #include "binomialnode.h" #include <iostream> #include <vector> #include <fstream> #include <sstream> #include <stdlib.h> #include <string> #include <stdio.h>  using namespace std; int main(int argc, char* argv[]) {     //input handling     if(argc != 2)     {         cout << "incorrect usage. \n example: ./a.out <filename>" << endl;         exit(1);     }     binomialtree *tree = new binomialtree();       char *buffer;     char *token;     //read file buffer.**************************************     string input;     ifstream file;     file.open(argv[1]);     if(file.is_open())     {         string str;         while(file.good())         {             getline(file,str);             input += " " + str;         }     }     else{         cout << "file not found"<< endl;         return 1;     }     file.close();      int buf;     stringstream ss(input);      vector<int> tokens;      while(ss >> buf)     {         tokens.push_back(buf);     }     int = 0;     for(i = 0; < tokens.size(); i++)         tree->insert(tokens[i]);     //end file reading *******************************************     delete tree; } 

binomialnode.h

#ifndef _binomialnode_h_ #define _binomialnode_h_ #include "binomialtree.h" class binomialnode {     public:          int k;         binomialnode *children[20];         int data;          binomialnode(); }; #endif 

binomialnode.cpp

class binomialnode {        binomialnode::binomialnode(int n)     {            this->k = 0;         this->data = n;     } } 

binomialtree.h

#ifndef _multimap_h_ #define _multimap_h_ #include "binomialnode.h"  class binomialtree {     public:         binomialnode * bq[20];           void insert(int n);         void merge(binomialnode *queue, binomialnode *in, int k);         void print(binomialnode *root, int tab); }; #endif 

binomialtree.cpp

#include "binomialnode.h" #include "binomialtree.h" #include <iostream> #include <cstdlib>   class binomialtree {     void binomialtree::insert(int n)     {         binomialnode *in = new binomialnode(n);         if(bq[0] == null)         {             bq[0] = in;             return;         }         else             merge(bq[0], in, 0);     }     void binomialtree::merge(binomialnode *queue, binomialnode *in, int k)     {         if(queue == null)         {             bq[k] = in;             return;         }         if(n == null)         {             bq[k] = queue;             return;         }         if(queue->data > in->data)         {                merge(in, queue);             return;         }         queue->k++;         binomialnode* temp[queue->k];         int i;         for(i = 0; < queue->k-1; i++)             temp[i] = queue->children[i];         temp[queue->k-1] = in;         for(i = 0; < queue->k; i++)             queue->children[i] = temp[i];         if(bq[queue->k] == null)         {             bq[queue->k] = queue;             return;         }         else             merge(queue, bq[queue->k]);     }     void binomialtree::print(binomialnode *root, int tab)     {         if(root == null)             return;         int i;         for(i = 0; < tab*5; i++) cout << " ";         cout << root->data << endl;         for(i = 0; < root->k; i++) print(root->children[i], tab+1);     } } 

you cpp files shouldn't have class in them. should more like:

binomialnode.cpp

#include "binomialnode.h"  binomialnode::binomialnode(int n) :   k(0) {   data = n; } 

and of course corollary longer binomialtree.cpp. also, should compile like:

g++ binomialtree.cpp binomialnode.cpp asg5.cpp -o asg5 

also you're going run lot of other problems code. instance:

binomialnode * bq[20]; 

i don't see bq being initialized anywhere, means you're pretty guaranteed seg fault if run this. need initialize or allocate it. seeing lines like:

if(bq[0] == null) 

makes me think wanted:

binomialnode bq[20]; 

though still need initialize nulls since aren't guaranteed full of nulls when run program. also, recursive , infinite , can't possibly work (in binomialnode.h):

binomialnode *children[20]; 

there more issues code, wasn't question, i'll stop now!