[jiggy2011]

upvoted for realloc trick

[haberman]

This inspired me to write one that is even shorter and doesn't heap-allocate any memory at all. What can I say, I'm a sucker for minimal C.

  #include <stdio.h>
  #include <stdlib.h>

  int main(int argc, char *argv[]) {
    int row = atoi(argv[1]);
    long data[row];
    for (int i = 0; i < row; i++) {
      data[i] = 1;
      for (int j = i - 1; j > 0; j--) data[j] += data[j - 1];
    }
    for (int i = 0; i < row; i++) printf("%ld ", data[i]);
    printf("\n");
    return 0;
  }

[demallien]

When did C start accepting non-constants for array size declarations?

[hn_reader]

I was wondering the same thing. But I can confirm it compiles and runs, though I had to supply a -std=c99 flag to gcc.

[demallien]

Ahhh, useful tip. I've just been using alloca instead...

[haberman]

Variable-length arrays were added in C99.

[hn_reader]

Best solution I've seen here so far.

[shaggyfrog]

If row is too big you can bust your stack frame when you define your data array.

[hn_reader]

True, though in this example integer overflow would happen first.

[kunqiana]

I think your code is off by 1.