Hello i have problem, how can i solve this?

[runic torrent]

#include <stdio.h>

int main()
{
    FILE *db;
    char file_name[255];
    float id, id_01, id_02, id_03, x,y,z;
    int win;
    
    printf("File name: ");
    scanf("%s", file_name);
    
    db =fopen(file_name, "r");
    if(db==NULL) {
        printf("FILE NOT FOUND");
    } else {
        while( fscanf(file_name,"%f %f %f %f",&id, &id_01, &id_02, &id_03)!= NULL){
        x+=id_01;
        y+=id_02;
        z+=id_03;
        }

        switch(win){
        case 1: { x>z&&x>y; }
        break;
        case 2: { y>x&&y>z; }
        break;
        case 3: { z>x&&z>y; }
        break;
        }
        return win;
    
    
}
return 0;
}```

CONSOLE LOG:

[shut prairie]

When your question is answered use !solved to mark the question as resolved.

Remember to ask specific questions, provide necessary details, and reduce your question to its simplest form. For tips on how to ask a good question use !howto ask.

[runic torrent]

I know the code could be better, but this is a exam problem so i must get to what teacher says

[hardy slate]

whats the question?

[tardy flame]

What is that switch-statement supposed to do?

[hardy slate]

oh you're passing a file name to fscanf not the file

[tardy flame]

Also instead of passing file_name you need to pass db to the fscanf call

[hardy slate]

snap

[runic torrent]

Im trying and is what is giving the problem, to get form a file determinate values

I have the next values
id id_01 id_02 id_03

and refers to politics results being id the place where they vote and 01 02 03 the users so i trying to get it in diferent forms

[tardy flame]

yeah, you got it be4 me :/

[tardy flame]

Im trying and is what is giving the problem, to get form a file determinate values
In English please?

[hardy slate]

I think its a matrix?

[runic torrent]

Sorry bad englis

[hardy slate]

and you want the determinant?

could be wrong

[runic torrent]

but someone told to change de file name and it worked

nice

how to solve this

I want to evoid some more lines of code

[hardy slate]

fscanf doesn't return a pointer

NULL is specifically for pointers

if you want to compare against 0 you should use 0

[runic torrent]

Okay

thanks all

But problem continues

Why this happen

But i can still enter text

nothing happen

I share it so can see problem

https://onlinegdb.com/6lvjW2DKB

[hardy slate]

ah you should probably be comparing against EOF rather/ as well as 0

[runic torrent]

what's EOF

[hardy slate]

EOF means end of file

[runic torrent]

Okay, will try

[hardy slate]

checking for 0 should error

checking for EOF should be when you stop looping

[runic torrent]

so i must put EOF?

Or how

i cannot imagine that

[hardy slate]

int res = fscanf(...);
if(res == 0) { /* error */ }
if(res == EOF) { /* end loop */ }
else {
  /* continue loop */
}

you're likely gonna need more than a simple while loop

OR

just replace 0 with EOF and assume there will be no error

and your simple while loop is fine

[runic torrent]

I cannot use more advanced code

Because teacher get mads

the thing is that i can continue writting

and dont know why

[shut prairie]

@runic torrent Has your question been resolved? If so, type !solved :)

[hardy slate]

have what you had before

where it stopped working the second time

go back to that

and replace 0 with EOF

don't have extra loops or whatever

[runic torrent]

It's working, nice

But still some problems

id id01 id02 id03 ain't getting their values

[hardy slate]

well your breakpoint is outside the loop

which is where you should be if you got to the end

and you don't have values

if you want to see values you need to break inside the loop

[runic torrent]

I don't get you

[hardy slate]

your switch isn't in the loop

your breakpoint is on the switch

if you want to see your values put your breakpoint inside the switch

OH well x y and z are 0 anyway lol

[runic torrent]

I get you now but if switch isnt working

i want to know why this doesn get the work done

those aren't getting their values

[hardy slate]

um

switch isn't working because you don't assign a value to win

speaking of that you never assign values to x y or z so you're doing illegal code currently

you need to assign initial values to a variable before you can use it

[runic torrent]

okay

but this ?

those aren't working too

[hardy slate]

yeahhhh idk could be a UB thing. YOu should fix UB before you think about that

UB means undefined behaviour

means youre doing something c says youre not allowed, but doesn't necessarily tell you you're not allowed (because in most cases you just want to assume its not happening rather than check for it)

and it can break a bunch of things

[runic torrent]

so what im doing wrong

[hardy slate]

using values you never assigned

e.g. win, x, y, z

int win; just says win exists, it doesn't say what value it has

int win = 0; means it starts as 0

its also entirely possible this only compiler doesn't work with multiple files

so whatever you do it will never load to other file properly

but idk

ive not used it

[runic torrent]

Im using 1 file only

and i have used more lot

still doesnt work

But this is good for taking 4 things?

[hardy slate]

yes

should be

can you just post the code here (not pictures)

[runic torrent]

#include <stdio.h>
#define n 0
int main(){
    FILE *db;
    char file_name[255], text[255];
    float id, id_01, id_02, id_03, x=0,y=0,z=0, all_01,all_02,all_03,half,result;
    int win=0, i;
    
    printf("File name: ");
    scanf("%s", file_name);
    
    db =fopen(file_name, "r");
    if(db==NULL){printf("FILE NOT FOUND\n"); return 0;} 
    printf("Text for db\n");
    while(fgets(text, 255, db)!= NULL) {
        printf("%s",text);
    }
    
   while( fscanf(db,"%f %f %f %f",&id, &id_01, &id_02, &id_03)!= EOF){
        x+=id_01;
        y+=id_02;
        z+=id_03;
        half = (id_01 + id_02 + id_03)/2;
        if (id_01>half) {}
        if (id_02>half) {}
        if (id_03>half) {}
       
   }
   
    if ( x>z&&x>y ) {
        printf("\nElections winner:");
    }
    if ( y>z&&y>x ) {
        printf("\nElections winner:");
    }
    if ( z>x&&z>y ) {
        printf("\nElections winner:");
    }

   /* switch(win){
        case 1: { x>z&&x>y; }
        break;
        case 2: { y>x&&y>z; }
        break;
        case 3: { z>x&&z>y; }
        break;
    }
    
    
   
    printf("\nElections winner:");
    */
    
fclose(db);
return 0;
}```

[hardy slate]

wooooah

where did this fgets come from

[runic torrent]

that's the only thing that works

some updates

[hardy slate]

you realise that fgets also move the file pointer forward

same as fscanf

so if you do an fgets you skip all the data

and now fscanf can't see it

[runic torrent]

i must get to the init

buddy here the thing i must do

There is an existing text file with information on the results of a vote. The file contains in four columns per line: the census tract identifier (one integer), the votes of party 1 (one integer), Party 2 votes (one integer) and Party 3 votes (one integer). The total number of lines in the file is unknown. It is requested: a) Write a program that asks the user for the name of an input file, opens it and displays it for a reason. screen all the contents of the file. (0.5 points). b) Reprocess the file and print in the main program which of the matches (1, 2 or 3) won the Elections. (1 point). c) Reprocess the file and print in how many census tracts there is a party with a majority absolute (more than half of the votes). (1.5 points).

[hardy slate]

well you need to fseek to the start of the file again in order to read from it a second time

fseek(stream, 0, SEEK_SET);

or rewind(stream)

[runic torrent]

redind

[hardy slate]

where stream is whatever file you want to do this to

[runic torrent]

rewind

buddy

it works

like shound

should

buddy im happy

thanks you

too much

really

I hope god is on your side

always

[shut prairie]

@runic torrent Has your question been resolved? If so, type !solved :)