Help on c++ (how to round correctly the pi value)

thank you very much guys... my problem is fixed...

here is the code for the first series.......

for (int long n=1; n<=10000 && flag!=1; n++)  //for loop for series 1 
{//star for loop series 1
 
	   pi1+= (4*pow(-1.0, n+1))/(2*n - 1);   //calculation series 1 
       pi12=ceil((pi1*pow( 10.0,digits ) )- 0.49  ) / pow( 10.0,digits ); //round the results 
	 if (pi12==result) //if check..... for the result
	 {//if check  start
	    flag=1;  // if pi12==result  flag== 1 
	 }//if check end 	  
	 else //else of the result
		 counter++; // if the program don't find the approximate series change iterations ( calculation of
iteratios)
 
}//loop end series 1 
        if (flag==1) // if check = 1 
	 {  // start if 
	   cout<<" Series "<<series<<" is approximate on "<<counter<<" iterations"<<" Series "<<series<<"
is "<<pi12<<endl; 
	   cin>>pi12; //cin the result to print 
	 } // if end 
	 else  // else of check
 
     cout<<" This series doesn't approximate on Value PI...."<<endl; //print error message....
	 cin>>pi;//cin the result to print 
 
}//end of if staytment series 1