Question

The program below is supposed to find the first all-zero row, if any, of an n × n matrix. Is this a correct approach to the problem, and is there another good structured approach to this code in C, or in any language in general? I’m trying to learn more about goto statements and appropriate uses/ alternatives to them. I appreciate any help!

int first_zero_row = -1; /* none */
int i, j;
for (i = 0; i < n; i++) {
    for (j = 0; j < n; j++) {
        if (A[i][j]) goto next;
    }
    first_zero_row = i;
    break;
    next: ;
}

Answer 1

I’m not against using goto in some situations, but I think this can be re-written like this:

for (i = 0; i < n; i++) {
    for (j = 0; j < n; j++) {
        if (A[i][j]) break;
    }
    if (j==n) { /* the row was all zeros */
        first_zero_row = i;
        break;
    }
}