C My professor said there is no way this code works...but it does and we don't know why.

[bouttreefiddy]

This was a a homework assignment to take the input of the mile time of three runners and return their time in m/s and ft/s. We had to create three functions. I wasn't too sure about functions so I just did some trial and error until it worked. When I submitted it, he gave me a 0 and said that there was no way that the code actually worked and to fix it... but it really does work. I talked to him about it and he said that it shouldn't work because I am using the return of "calc_seconds" (which just converts the inputted minutes/seconds into straight seconds) from the first function to calculate the m/s and ft/s in their respective functions. Since the functions can't talk to each other directly, it shouldn't work, right? I know it says not to just paste a wall of code but I feel like I have to include all of it since I don't know what could be making it work. Like I said, I have tried it with dozens of numbers and it's always correct. It's probably not the most well written code but I am just getting started learning it.

#include <stdio.h>

//constants
#define FEET_PER_MILE 5280
#define METERS_PER_MILE 1609.34

//function protypes
int time_in_seconds(int minutes, int seconds);
double feet_per_second(int minutes, int seconds);
double meters_per_second(int minutes, int seconds);


int main(void)
{
  int input_minutes, input_seconds, out_seconds;
  double fps, mps;

  printf("Enter Runner 1's time in minutes and seconds.\n");
  scanf("%d" "%d", &input_minutes, &input_seconds); //get input
  out_seconds = time_in_seconds(input_minutes, input_seconds);  //call functions
  fps = feet_per_second(out_seconds, FEET_PER_MILE);
  mps = meters_per_second(out_seconds, METERS_PER_MILE);
  printf("Runner 1 ran the mile in %d minutes and %d seconds at a speed of %.3lf feet per second, or %.3lf meters per second.\n\n", input_minutes, input_seconds, fps, mps); //display outputs

  printf("Enter Runner 2's time in minutes and seconds.\n");
  scanf("%d" "%d", &input_minutes, &input_seconds);
  out_seconds = time_in_seconds(input_minutes, input_seconds);
  fps = feet_per_second(out_seconds, FEET_PER_MILE);
  mps = meters_per_second(out_seconds, METERS_PER_MILE);
  printf("Runner 2 ran the mile in %d minutes and %d seconds at a speed of %.3lf feet per second, or %.3lf meters per second.\n\n", input_minutes, input_seconds, fps, mps);

  printf("Enter Runner 3's time in minutes and seconds.\n");
  scanf("%d" "%d", &input_minutes, &input_seconds);
  out_seconds = time_in_seconds(input_minutes, input_seconds);
  fps = feet_per_second(out_seconds, FEET_PER_MILE);
  mps = meters_per_second(out_seconds, METERS_PER_MILE);
  printf("Runner 3 ran the mile in %d minutes and %d seconds at a speed of %.3lf feet per second, or %.3lf meters per second.\n", input_minutes, input_seconds, fps, mps);

return 0;
}

//function definitions

//calculate total seconds
int time_in_seconds(int minutes, int seconds)
{
  int calc_seconds;
  calc_seconds = (minutes*60)+seconds;
  return calc_seconds;

}
//calculate fps
double feet_per_second(int minutes, int seconds)
{
  double calc_fps;
  int calc_seconds;
  calc_fps = (double)FEET_PER_MILE/calc_seconds;
  return calc_fps;

}
//calculate mps
double meters_per_second(int minutes, int seconds)
{
  double calc_mps;
  int calc_seconds;
  calc_mps = (double)METERS_PER_MILE/calc_seconds;
  return calc_mps;
}

 

[LTomy]

Hello bouttreefiddy,

Waaahh, gave you 0, kind of rude .

I must say your code is pretty clean.

There is a small problem in the functions 'feet_per_second, and 'meters_per_second'. You are using the variable 'calc_seconds;':

calc_mps = (double)METERS_PER_MILE/calc_seconds;

But you did not set its value...:

int calc_seconds;

You also do not use the argument 'minutes'.

The arguments you give the function 'meters_per_second' do not seem to match what it expects:
mps = meters_per_second(out_seconds, METERS_PER_MILE);
double meters_per_second(int minutes, int seconds)