Unknown problem[SOLVED]

[bySLiTz]

I'm a really noob programming, I mean that I don't have any idea on what I'm doing but somehow I decided to write a little program just for fun.

Since my C's knowledge is just awful because the last time I used something even close was months before, I have no idea why this thingy thing doesn't work.

 

 

//MRU

#include <stdio.h>
#include <math.h>

int main () {
    //MRU x=p+v(t-y)
    double x,p,v,t,y,q,w,e,r,u;
    
    printf ("                                       MRU\nIntroduzca los datos\nPresione '0' si no conoce el valor\n\n");
    printf ("Distancia final:\n");
    scanf ("%d.", &x);
    printf ("Distancia inicial:\n");
    scanf ("%d.", &p);
    printf ("Velocidad:\n");
    scanf ("%d.", &v);
    printf ("Tiempo final:\n");
    scanf ("%d.", &t);
    printf ("Tiempo inicial:\n");
    scanf ("%d.", &y);
    
    if (x==0) {
        q==p+v*(t-y);
        printf ("La distancia final es %f.",q);
    }
    if (p==0) {
        w==x-v*(t-y);
        printf ("La distancia inicial es %f.",w);
    }
    if (v==0) {
        e==(x-p)/(t-y);
        printf ("La velocidad es %f.",e);
    }
    if (t==0) {
        r==(x-p-v*y)/v;
        printf ("El tiempo final es %f.",r);
    }
    if (y==0) {
        u==(p+v*t-x)/v;
        printf ("El tiempo inicial es %f.",u);
    }
    
    return 0;
}

 

It is on Spanish but feel free to edit it and do whatever you want with the code since it is garbage

 

Thanks

 

[Enderman]

in scanf %d is for integers

you need to use %lf for doubles

[bySLiTz]

1 minute ago, Enderman said:

in scanf %d is for integers

you need to use %lf for doubles

OK, thanks but It continues giving me 0 as a result (I you traduce the printfs you will understand what I want to do [I'll fix the "Introduce '0' if you don't have the value" thing])

 

[Enderman]

3 minutes ago, bySLiTz said:

OK, thanks but It continues giving me 0 as a result (I you traduce the printfs you will understand what I want to do [I'll fix the "Introduce '0' if you don't have the value" thing])

 

if you remove one of the statements from an if does it still give you 0?

try printing %f instead of %f. and see if that makes a difference

[bySLiTz]

2 minutes ago, Enderman said:

if you remove one of the statements from an if does it still give you 0?

try printing %f instead of %f. and see if that makes a difference

Same

What I want to do is a program that ask you for the values of x, p, v, t and y that follows the next equation x=p+v(t-y). If you don't have one of these, you just type 0 (I'll do this another way, don't worry) and the program will give you the value of the variable you don't have the value of.

[Enderman]

4 minutes ago, bySLiTz said:

Same

What I want to do is a program that ask you for the values of x, p, v, t and y that follows the next equation x=p+v(t-y). If you don't have one of these, you just type 0 (I'll do this another way, don't worry) and the program will give you the value of the variable you don't have the value of.

yeah i know what you want the program to do

i found what the issue is though

 

when youre doing 

q==p+v*(t-y);

on all your equations youre using == instead of =

== just compares the two and says true or false

= is what you need to use to set p equal to the answer

[bySLiTz]

4 minutes ago, Enderman said:

yeah i know what you want the program to do

i found what the issue is though

 

when youre doing 

q==p+v*(t-y);

on all your equations youre using == instead of =

== just compares the two and says true or false

= is what you need to use to set p equal to the answer

Holy thanks, I didn't realised that I had used == and not =.

Thanks I really aprecciate it.

Now that we fixed it. Do you know how can I pass a scanf and then see if the variable have data or not to execute the if or not instead of using 0s since they can appear normally in the equation. Maybe what I want the way I'm doing it, is impossible but maybe you can come out with an idea to do it.

Thanks

[Enderman]

4 minutes ago, bySLiTz said:

Holy thanks, I didn't realised that I had used == and not =.

Thanks I really aprecciate it.

Now that we fixed it. Do you know how can I pass a scanf and then see if the variable have data or not to execute the if or not instead of using 0s since they can appear normally in the equation. Maybe what I want the way I'm doing it, is impossible but maybe you can come out with an idea to do it.

Thanks

hm
usually for stuff like this -1 is used to indicate "no value"

 

not sure if that would work for you though, maybe you want to calculate with negative values too

in which case you would need to put in something other than a number, and idk what happens if you give a character to scanf expecting a double

there must be some way of detecting that, but ive only been doing C for a few weeks so idk yet

[bySLiTz]

1 minute ago, Enderman said:

hm
usually for stuff like this -1 is used to indicate "no value"

 

not sure if that would work for you though, maybe you want to calculate with negative values too

in which case you would need to put in something other than a number, and idk what happens if you give a character to scanf expecting a double

there must be some way of detecting that, but ive only been doing C for a few weeks so idk yet

What languages do you use?

[Enderman]

1 minute ago, bySLiTz said:

What languages do you use?

C++ python and just started C

[bySLiTz]

Just now, Enderman said:

C++ python and just started C

Could you try to do the scanf's thing on C++ or even Python to see if an idea appears to me?

[Enderman]

1 minute ago, bySLiTz said:

Could you try to do the scanf's thing on C++ or even Python to see if an idea appears to me?

scanf is only C

python is raw_input() and C++ is cin>>

so yeah not really

 

but i have found this

http://stackoverflow.com/questions/1681873/how-to-make-sure-input-is-a-double-in-the-c-programming-language

i think you can use this to check if the input was a double or not

so you could input some letter instead of a number and make it know that that is what you want to calculate

 

but thats a lot harder than just detecting -1 or not

[bySLiTz]

1 minute ago, Enderman said:

scanf is only C

python is raw_input() and C++ is cin>>

so yeah not really

 

but i have found this

http://stackoverflow.com/questions/1681873/how-to-make-sure-input-is-a-double-in-the-c-programming-language

i think you can use this to check if the input was a double or not

so you could input some letter instead of a number and make it know that that is what you want to calculate

 

but thats a lot harder than just detecting -1 or not

Yeah, I didn't mean with scanf, just the way the language gets data from the user

[Enderman]

2 minutes ago, bySLiTz said:

Yeah, I didn't mean with scanf, just the way the language gets data from the user

well C++ and python are different cause raw input and cin can take anything

but in C scanf needs the % thingy to specify what the input is

[bySLiTz]

2 minutes ago, Enderman said:

well C++ and python are different cause raw input and cin can take anything

but in C scanf needs the % thingy to specify what the input is

I didn't know that. Thanks You anyway.

I'll try to fix that thing myself