What am I doing wrong.

[alex1067]

The assignment calls for :

DIRECTIONS: Write a C program which prompts the user
for a start time and an end time. Each time has the
format hh:mm (hours: minutes). Your program should
compute and display the elapsed time difference
in seconds. This should be followed immediately by
'PROGRAM ENDS' Do not include the single quotes.


Heres what I have:
insert

     7  #include <stdio.h>
     8
     9   int main(void)
    10  {
    11
    12  int i, j, k, l, m;
    13
    14  m = (3600*k + 60*l) - (3600*i + 60*j);
    15
    16  printf("Please enter a start time in hh:mm format.\n");
    17  scanf("%d:%d", &i, &j);
    18  printf("Please enter an end time in hh:mm format.\n");
    19  scanf("%d:%d", &k, &l);
    20  printf("elapsed_time : %d\n", m);
    21  printf("PROGRAM ENDS\n");
    22                                                      
    23  return 0;
    24  }
insert

Whenever I run the prgram, it gives me the value -28860 ? What is wrong?

[robatino]

You're attempting to compute m BEFORE setting the values of i, j, k, and l.

[alex1067]

So the equation for m needs to go before the the last printf statement?

[robatino]

It needs to go after the two scanf() statements which input i, j, k, and l, and before the printf() statement which prints m (in other words, between current lines 19 and 20). You can't print m until you've computed it, and you can't compute it until you set i, j, k, and l.

[alex1067]

Ok thank you very much. Your recommendation worked. Sorry for the newbie question.

[Elysia]

I also suggest you give the variables proper names.