# whileloop/running total problem

• 01-22-2012
psynt555
whileloop/running total problem
hi i have been asked to input 2 integers, a drivers MILES and LITRES of fuel they have used.. i am then meant to printf the miles per litre for that specific entry AND a running total of the combined MPL's added so far...

Code:

```#include <stdio.h> int main( ) { int miles; int litres; int tanks; int mpl; int totalmpl; int counter; while ( miles > 0, counter++ ) {         printf("please enter the amount of miles you have driven, alternatavely, press 0 to finish the script.\n");         scanf("%d", &miles);         printf("please enter the amount of litres you used\n");         scanf("%d", &litres);         mpl=miles/litres;         printf("the number of miles per litre you have gained is:%d\n", mpl);         while (counter > 1)                 {                 totalmpl=mpl+mpl;                 printf("the total running miles per litre is:%d\n", totalmpl);                 } }   return 0; }```
this outputs nothing, if anyone can help i would be delighted. THANKS :)
• 01-22-2012
stahta01
FYI: You code has no running total in it.

Code:

`totalmpl=mpl+mpl;`
With the idea that you want a running total.

Code:

`totalmpl=totalmpl+mpl;`
Edit: Your code makes little sense to me.

Code:

`while (counter > 1)`
Is there any reason to believe the value of counter is changing inside the loop?
I say no, therefor the loop will never run or be endless!

Tim S.
• 01-22-2012
MK27
Quote:

while ( miles > 0, counter++ )
Since miles is uninitialized at this point, it is just as likely to be negative as positive. You need to initialize it to 1 or something first. The same is even more true for counter, altho I actually don't see counter as serving any useful purpose here. Just add mpl to total (total should be initialized to 0 -- that's three uninitialized variables that need to be, tch) and get rid of counter.