Thread: how to properly indent and format a source code?

Hello.

I want to learn how to indent and format properly my source codes. I have found this online:

https://en.wikipedia.org/wiki/Indent_style
GNU Coding Standards: Formatting

Here is a source code that I wrote where I was criticized that it is not correctly formated:

why this code is not working? i wanted to multiply a matrix by itself

Code:

#include <stdio.h>
  
int main()
{
    int i,j;
    int array1[3][3]= {{0,0,0},{0,12,36},{0,32,56}} ;
    int sqr[3][3];
 
    /* multiplication part */
    for(i=0;i<3;i++)
    {
           for(j=0;j<3;j++){
                              sqr[i][j]=array1[i][0]*array1[0][j]+array1[i][1]*array1[1][j]+array1[i][2]*array1[2][j];
                           }
    }
 
 
 
    /* here is the printing part */
    for(i=0;i<3;i++)
    {
        for(j=0;j<3;j++){
                        printf("%d\t",sqr[i][j]);
                        }
        printf("\n");
    }
    return 0;
}

1) What does it mean to properly indent a code? >> I think that this is pretty clearly explained in the wikipedia article and I think that I already do that right, even in the example

2) What does it mean to properly indent a code? >> Does it mean two empty lines between code? What more?

Thank you.

A corrected version:

Code:

#include <stdio.h>
  
int main()
{
    int i,j;
    int array1[3][3]= {{0,0,0},{0,12,36},{0,32,56}} ;
    int sqr[3][3];
 

    /* multiplication part */
    for(i=0;i<3;i++)
    {
        for(j=0;j<3;j++){
                           sqr[i][j]=array1[i][0]*array1[0][j]+array1[i][1]*array1[1][j]+array1[i][2]*array1[2][j];
                        }
    }


    /* here is the printing part */
    for(i=0;i<3;i++)
    {
        for(j=0;j<3;j++){
                        printf("%d\t",sqr[i][j]);
                        }
        printf("\n");
    }


    return 0;
}