Thread: Recursion problem

I´m having a problem with a recursive function. When the stop condition verifies:

Code:

if(j>nodes && source==in)
return maxpeso;

i want the function to stop and return to main,where there is printf("%d\n",maxpeso);, which is the result of the recursive function.The problem is,when the condition holds , i want the function to return to main,but the function continues and enter an infinite cycle...How can i stop the execution of the function and return to main just for the printf?

here´s the function:

Code:

int maxpeso=0;
void max_peso(int source, int sink, int nodes,int j)
{
	int num;
	int u=0,n=0;
	
	if(j>nodes && source==in)
	{
		;
		

	}
	else
	{	

	if(source == sink)
		poe_na_fila(source);
	else
		{
			if(j> nodes)
			{
				percurso[coroa]=0;
				coroa -=1;
				max_peso(percurso[coroa],sink,nodes,source+1);
			}
			else
			{
	
			if(adj[source][j]==oo)
				max_peso(source, sink, nodes,j+1);
			else
				{
					poe_na_fila(source);
					max_peso(j, sink, nodes,0);
				}
			}
			
		}
	n=somador(percurso,nodes);
	if(n>maxpeso)
		maxpeso=n;
	coroa=coroa-1;
	percurso[coroa]=0;
	coroa=coroa-1;
	max_peso(percurso[coroa],sink, nodes, source+1);
	}

}
main (int argc, char *argv[])
{
	int noi,nof,peso,i,u,j,arcos,nos,inicio,fim;
	inicio=fim=noi=nof=i=j=peso=arcos=nos=u=0;
	FILE *fp;
	fp=fopen(argv[1],"r");
	if (fp==NULL)
		printf("Impossível abrir o ficheiro %s", argv[1]);
	else
		{
			fscanf(fp,"%d",&nos);
			fscanf(fp,"%d",&arcos);
			for(u=0;u<=nos;u++)
			{
				percurso[u]=0;
			}
			for(i=0; i<=nos;i++)
			{
				for(j=0;j<=nos;j++)
					adj[i][j]=oo;
			}
			for(i=0;i<arcos;i++)
			{
				
				fscanf(fp,"%d %d %d", &noi,&nof,&peso);
				adj[noi][nof]=peso;
			}
			fscanf(fp,"%d %d", &inicio, &fim);
			in=inicio;
			max_peso(inicio,fim,nos,0);
		printf("%d\n",maxpeso);
		}
}

I want it to stop at the if(j>nodes && source==in) condition and return to main to do the printf

This is probably the best method as it unwinds the stack.

Code:

void max_peso(int source, int sink, int nodes,int j)
{
    if(j>nodes && source==in)
    {
         throw 123;      // error code
    }
}

main (int argc, char *argv[])
{
    try
    {
         max_peso(inicio,fim,nos,0);
    }
    catch(int rc)
    {
          printf("max_peso Error code = %d\n",rc);
    }
}

Huuhhh guys...what the heck is that try,catch,throw thing...?How do i change my code to use that?

Right...So...How can i solve the problem?Is there any way of stopping the execution of the function..?

it worked,thnks!

You could do a returns after max_peso call to stop following lines of code being run before the function ended.

Code:

int max_peso(int source, int sink, int nodes,int j)
{
	int num;
	int u=0,n=0;
	
	if(j>nodes && source==in)
	{
		return 1;
	}
	else
	{	

	if(source == sink)
		poe_na_fila(source);
	else
		{
			if(j> nodes)
			{
				percurso[coroa]=0;
				coroa -=1;
 				if(max_peso(percurso[coroa],sink,nodes,source+1)) return 1;

			}
			else
			{
	
			if(adj[source][j]==oo)
				if(max_peso(source, sink, nodes,j+1)) return 1;
			else
				{
					poe_na_fila(source);
					if(max_peso(j, sink, nodes,0)) return 1;
				}
			}
			
		}
	n=somador(percurso,nodes);
	if(n>maxpeso)
		maxpeso=n;
	coroa=coroa-1;
	percurso[coroa]=0;
	coroa=coroa-1;
	if(max_peso(percurso[coroa],sink, nodes, source+1)) return 1;
	}
	return 0;
}