Thread: I have a error can somebody help ?

I have this code :

Code:

// Grafuri.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <stdlib.h>
#include <process.h>

#define clrscr() system("cls");

struct sarc;

typedef struct snod{
	struct snod *urm;
	struct sarc *a;
	int cheie;
} nod;

typedef struct sarc{
	nod *n;
	struct sarc *urm;
}arc;

nod *h_nod=NULL;

//arc *caut_arc(nod *, nod *); // cauta arc
//arc *caut_arc(int n1, int n2,int *, nod *, nod *); //cauta arc
nod *caut_nod(nod *, int); // cauta nod 
nod *add_nod(nod*,int); // adauga un nod;
arc *add_arc(arc*, int,int); // adauga un arc intre 2 noduri;

nod *caut_nod(nod *lista, int cheie)
{ 
   nod *q1;

   for (q1=lista; q1!=NULL && q1->cheie < cheie; q1=q1->urm); 

   if (q1!=NULL && q1->cheie == cheie) 
      return q1; 

   return NULL;
} /*caut nod*/

arc *cauta_arc(nod *n1, nod *n2){
	
	if (n1==NULL || n2==NULL) return NULL;
	arc *q1;

	for (q1=n1->a; q1!=NULL && q1->n->cheie < n2->cheie; q1=q1->urm); 

	if (q1!=NULL && q1->n->cheie == n2->cheie) 
		return q1; 
	
	return NULL;

} /*caut arc*/

arc *caut_arc(int n1, int n2 ,nod *nodr1, nod *nodr2 ,int *err=NULL)
{ 
    nod *nod1,*nod2;
	
	if ((nod1=caut_nod(h_nod,n1))==NULL) {
		printf("Nu exista primul nod: %d",n1);
		if (err!=NULL) *err=1;
		return NULL;
	}

	if ((nod2=caut_nod(h_nod,n1))==NULL) {
		printf("Nu exista al doilea nod: %d",n2);
		if (err!=NULL) *err=2;
		return NULL;
	}
	
	if (err!=NULL) *err=0;
	if (nodr1!=NULL) nodr1=nod1;
	if (nodr2!=NULL) nodr2=nod2;

	return cauta_arc(nod1,nod2);
} /*caut_arc*/

nod *add_nod(nod *lista, int v)
{
   nod *q1, *q2, *aux;

   if (caut_nod(lista,v)!=NULL){
		printf("Nodul %d exista deja\n",v);	
		return lista;
   }

   if ((aux=(nod *)malloc(sizeof(nod)))==NULL) 
   {
      printf("Eroare: memorie insuficienta\n");
      exit(1); 
   }

   aux->a=NULL; aux->cheie=v;   

   for (q2=q1=lista; q1!=NULL && q1->cheie < v; 
        q2=q1, q1=q1->urm); 

   if (q1!=NULL && q1->cheie == v)
   {
      printf("Eroare: Nodul %d apare in tabela\n", v);
      return lista;
   }

   if (q1!=q2) /* daca inserarea nu se face la inceputul listei*/
   {
      q2->urm=aux;
      aux->urm=q1;
      return lista ;
   }

   /* daca inserarea se face la inceputul listei */

   aux->urm=lista;
   return aux;
}/* add_nod */

int add_arc(int n1, int n2){
	arc *q1, *q2, *aux;
	nod *nod1;
	nod *nod2;
	nod *l1,*l2;
	int err;
	
	if ((aux=caut_arc(n1,n2,nod1,nod2,&err))!=NULL) {
		printf("Exista deja un arc intre nodurile: %d,%d",n1,n2);
		return 3;
	}

	if (err) return err;
	/*nod1=caut_nod(h_nod,n1);
	nod2=caut_nod(h_nod,n2);*/

	if ((aux=(arc *)malloc(sizeof(arc)))==NULL) 
	{
		printf("Eroare: memorie insuficienta\n");
		exit(1); 
	}
	aux->n=NULL;  

	for (q2=q1=nod1->a; q1!=NULL && q1->n->cheie < n2; 
	q2=q1, q1=q1->urm); 

	if (q1!=NULL && q1->n->cheie == n2) // Nu ar trebuii sa se indplineasca aceasta conditie
	{
	   //	printf("Eroare: %s apare in tabela\n", s);
		return 3;
	}

	if (q1!=q2) /* daca inserarea nu se face la inceputul listei*/
	{
		q2->urm=aux;
		aux->urm=q1;
		return 0;
	}

	/* daca inserarea se face la inceputul listei */

	aux->urm=nod1->a;
	nod1->a=aux;
	return 0;
}

void intr(){

	h_nod=add_nod(h_nod,1);
	h_nod=add_nod(h_nod,3);
	h_nod=add_nod(h_nod,2);
	h_nod=add_nod(h_nod,1);
	h_nod=add_nod(h_nod,5);
	add_arc(1,3);
	add_arc(3,5);
	add_arc(5,1);
	add_arc(1,3);
}
int main(int argc, char* argv[])
{
	intr();
	return 0;
}

when I call the function aux=caut_arc(n1,n2,nod1,nod2,&err)) in add_arc I becam the following error :The variable 'nod2' is being used without being defined.

Can somebody help me ?

Because you're passing a pointer w/o initializing it.
This is also C code, not C++.
You also have errors of passing a pointer to a function that expects a pointer and not the address of a variable. To make things worse, your pointer is unitialized, unallocated, so your program is a ticking time bomb.

Where is C++? All I see is C. Bundles and bundles of C.

I see. So that's now allowed in C, huh?