Read integers from stdin and store in 2d array (C) - c

Question

I'm trying to read a text file containing integers via stdin and store the values in a 9x9 array (please note that the file must be read via stdin and not as an arg)
This is what I have:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
int main()
{
int puzzle[9][9];
int i,j,count=0;
char value[81];
for( i = 0; i < 9; i++ ) {
for( j = 0; j < 9; j++ ) {
scanf("%c", &value[count]);
puzzle[i][j] = value[count] - '0';
count++;
}
}
}
But it doesn't seem to convert the ASCII characters from scanf to int, which is what I thought the value[count] - '0' was supposed to do, so I end up getting values like this:
-16-16-160-16-160-16-161
Basically i'm trying to do exactly whats described in this thread, but in C instead of C++:
How to convert a 2d char array to a 2d int array?
Edit -
The input file looks like this (contains both white space and new lines):
0 0 1 9 0 0 0 0 8
6 0 0 0 8 5 0 3 0
0 0 7 0 6 0 1 0 0
0 3 4 0 9 0 0 0 0
0 0 0 5 0 4 0 0 0
0 0 0 0 1 0 4 2 0
0 0 5 0 7 0 9 0 0
0 1 0 8 6 0 0 0 7
7 0 0 0 0 9 2 0 0

Answer 1

The problem is not with the conversion line puzzle[i][j] = value[count] - '0';. The problem lies with the following scanf() statement, scanf("%c", &value[count]);. The scanf is reading the first white space. Use scanf(" %c", &value[count]); to read the input.

Answer 2

%c does eactly what it should: it reads one character. D'oh, it's whitespace? That doesn't matter. This is why...
... you shouldn't use %c but %d for scanning integers;
...you shouldn't use scanf() at all for something simple like this.
What I'd do if I were you:
int matrix[9][9];
int i = 0;
char buf[0x100];
while (fgets(buf, sizeof(buf), stdin)) {
char *end;
char *p = strtok_r(buf, " ", &end);
while (p) {
matrix[i / 9][i % 9] = strtol(p, NULL, 10);
i++;
p = strtok_r(NULL, " ", &end);
}
}

Answer 3

Is there any reason this doesn't work? Scan them in as integers.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
int main()
{
int puzzle[9][9];
int i,j,count=0;
char value[81];
for( i = 0; i < 9; i++ ) {
for( j = 0; j < 9; j++ ) {
scanf("%d", &value[count]);
puzzle[i][j] = value[count];
printf("%d", puzzle[i][j]); //to verify it is stored correctly
count++;
}
}
}
EDIT: since you said it's coming from a file, i copy/pasted the sample file you gave into C:\file.txt, and the following code appears to work just dandy.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
int main()
{
FILE *fp;
int puzzle[9][9];
int i,j,count=0;
int value[81];
fp = fopen("C:\\file.txt", "r");
for( i = 0; i < 9; i++ ) {
for( j = 0; j < 9; j++ ) {
fscanf(fp, " %d", &value[count]);
puzzle[i][j] = value[count];
printf("element %d is %d\n",count, puzzle[i][j]);
count++;
}
}
}