Thread: Multiplying Array Based Stacks?

How would one go about doing this? It's like doing second grade multiplication, like:

Code:

  1234
    11
  ____
  1234
 12340
+
 13574

like that. I'm trying alot of different things but ive managed to come up with some really buggy code. When responding, don't just give me code, but suggestions on what to do change/do. Heres my function. It makes use of push, pop, etc.

Code:

stack multiply(stack stackOne, stack stackTwo)
{
     stack copyStack;
     copyStack.top = -1;
     stack carry;
     carry.top = -1;
     stack runOne;
     runOne.top = -1;
     
     int x, y, limitOne, limitTwo, lhs, rhs, test, quotient, carryInt, total = 0, digit;
     int limitThree, z;
     limitOne = stackOne.top;
     limitTwo = stackTwo.top;
     
     for(x = 0; x <= limitTwo; x++)
     {
           copyStack = stackOne;
           pop(&stackTwo, &rhs);
           
           for(y = 0; y <= limitOne; y++)
           {
                 if(test = isEmpty(&copyStack) != 1)
                         lhs = 1;
                 else 
                      pop(&copyStack, &lhs);
                 
                 if(test = isEmpty(&carry) != 1)
                         carryInt = 0;
                 else
                     pop(&carry, &carryInt);
                     
                 quotient = (lhs * rhs) + carryInt;
                 
                 if(quotient > 10)
                 {
                      digit = quotient % 10;
                      push(&runOne, digit);
                      carryInt = (quotient - digit) / 10;
                      push(&carry, carryInt);
                 }
                 else if(quotient == 10)
                 {
                      push(&runOne, 0);
                      push(&carry, 1);
                 }
                 else if(quotient < 10)
                 {
                      push(&runOne, quotient);
                      }
                 if(y == stackTwo.top-1)
                 {
                      limitThree = carry.top;
                      for(z = 0; z <= limitThree; z++)
                            pop(&carry, &carryInt);
                            push(&runOne, carryInt);
                 }
           }
     }     
     return runOne;             
}

test is for the function isEmpty. if ifEmpty returns 0, than stack is not empty. otherwise itll return empty