/in/foo.c: In function 'main':
/in/foo.c:10:21: error: subscripted value is neither array nor pointer nor vector
    scanf("%d", &a[i][j]);
                     ^
/in/foo.c:14:11: error: subscripted value is neither array nor pointer nor vector
    if(a[i][j]==1)
           ^
/in/foo.c:7:6: warning: variable 'a' set but not used [-Wunused-but-set-variable]
  int a[10000];
      ^