Thread: Help/Suggestions with Iteration

If you read my original post, I have edited it to show the solution I have come up with. I have been able to devise an algorithm to multiply two polynomials through the iteration and I have traced the general idea and it works. But currently, it does not work in my program and I have a good feeling that it has to do with the for loops inside the while loop, but I can't nail the exact problem. Can someone provide a hint as to what is the problem is so that I can get back on track? Thanks.

Code:

 int sizeA = tmpPoly.PolyTerms.size();
 int size = b.PolyTerms.size();
 
 while(sizeA > 0)
 {
  for(It = tmpPoly.PolyTerms.begin(); It != tmpPoly.PolyTerms.end(); ++It)
  {       
   for(It2 = tmpPoly2.PolyTerms.begin(); It2 != tmpPoly2.PolyTerms.end(); ++It2)       
   {
    exp = (*It) + (*It2);
           
    size--;
    
    ++It;
    ++It2; 
   
    coeff = (*It) * (*It2);
    
    tPoly.PolyTerms.push_back(exp);
    tPoly.PolyTerms.push_back(coeff);
    
    size--;  
    
    if(size > 0) //size of the second polynomial
    {
     //reset It iterator to first term since there are still more terms to 
     //multiply in the second polynomial.
     It = tmpPoly.PolyTerms.begin();    
    }
    
    //If the size of tmpPoly2 is 0 then 
    //we have multiplied all of the terms in tmpPoly2 by the first term in 
    //tmpPoly but tmpPoly still has more terms. So since tmpPoly has an exp 
    //followed by coefficient, subtract 2 from sizeA, and delete the first pair of
    //exponent, coefficient and the while loop should repeat the process. Also,
    //tmpPoly2 size is reset.
   
   sizeA = (sizeA - 2);
   cout << "SizeA is: " << sizeA << endl;
   
   if(size == 0)
   {    
     //remove first two enties in tmpPoly
     for(int i = 0; i < 2; i++)
     {
      It = tmpPoly.PolyTerms.begin();
      tmpPoly.PolyTerms.erase(It);
     } 
    
     It2 = tmpPoly2.PolyTerms.begin();
     size = tmpPoly2.PolyTerms.size();
   } 
   
   if(sizeA == 0)
   {
    cout << "sizeA is 0. We're finished!: " << sizeA << endl;
    break;
   } 
   
   }//end tmpPoly2 for loop
  }//end tmpPoly for loop
  
 }//end while
...