How to print a "neat" 2D array in C - c

Question

I am able to print out a 2D array into an output file but it is not uniform. I would like to have the 2D array evenly spaced when it is printed out. I am fairly new at programing in C so any help would be greatly appreciated!
My Code:
#include <stdio.h>
#include <stdlib.h>
/**
* Driver method for program
*/
int main()
{
int nums[200];
int i = 0;
int j = 0;
FILE * in_file;
FILE * out_file;
srand(time(0)); //seed for random generator
/**
* if loop reads text file and stores numbers into array
*/
if (in_file = fopen("Data.txt", "r")) {
while (fscanf(in_file, "%d", &nums[i]) != EOF) {
i++;
}
int numbsinfile = i;
int random = randomNumber(2, 12);
int matrix1[5][random];
int matrix2[random][5];
out_file = fopen("out.txt", "w");
fprintf(out_file, "Matrix 1: \n");
fprintf(out_file, "Rows = 5 \n");
fprintf(out_file, "Columns = %d \n\n", random);
for(i = 0; i < 5; i++ ){
for(j = 0; j < random; j++){
int rand = randomNumber(0, numbsinfile);
matrix1[i][j] = nums[rand];
fprintf(out_file, "%d \t\t", matrix1[i][j]);
}
fprintf(out_file, "\n");
}
fclose(in_file);
fclose(out_file);
}
return 0;
}
/**
* Generates and prints random
* numbers in range [lower, upper].
*/
int randomNumber(int lower, int upper) {
int num = (rand() % (upper - lower + 1)) + lower;
return num;
}
The input file I am using along with the output file that my code produces. I am basically just wanting to clean up the 2D array that is printed to the output file.
input file:
23 34 -54 21 45 34 65 -54 21 45 34 65 -34 24 58
49 45 10 -57 20
57 39 20 58 23 10 20 58 -60 76 -82 28
28 -37 49 358 47 -50 37 29
57 -29 -20 47 69
93 57 23 49 -38 49 27 -40 48 39
56 -30 47 28 49
37 49
27 26 10 20 58 -60 26 10 20 58 -60 76 -82 28
28 -37 49 -28 93 28
73 47 27 83 37 -29 40 37 49 20
17 -26 12 17 17
18 38 29 39 -118
19 10 20 58 -60 76 -82 28
28 -37 49 59 10 58 -60 76 -82 28
28 -37 49 59 10 20 58 -60 76 -82 28
28 -37 49 30 -58 58 38 49 30 -58 58 38
49 30 -58 58 38
28 39
39 48 23 -50 28
48 29 39 40 29
My output file:
Matrix 1:
Rows = 5
Columns = 12
28 39 20 49 58 76 37 -26 47 -40 216309856 26
57 -50 30 47 29 58 73 20 26 216309856 49 26
216309856 30 59 45 20 23 -50 83 -50 -37 28 30
10 10 23 28 47 45 34 10 19 -38 -118 28
47 49 -40 20 49 29 10 20 58 69 10 28

Answer 1

How to print a “neat” 2D array in C (?)
Find the longest text width using snprintf(NULL, 0, some_format, ...
int width = 1;
for(i = 0; i < 5; i++ ) {
for(j = 0; j < random; j++) {
int rand = randomNumber(0, numbsinfile);
matrix1[i][j] = nums[rand];
int w = snprintf(NULL, 0, "%d", matrix1[i][j]);
if (w > width) width = w;
}
}
Use * in the specifier and width for printing.
for(i = 0; i < 5; i++ ) {
for(j = 0; j < random; j++) {
fprintf(out_file, " %*d", width, matrix1[i][j]);
}
fprintf(out_file, "\n");
}