/in/foo.c: In function 'main':
/in/foo.c:25:30: error: 'j' undeclared (first use in this function)
  else if(a[i]==0){cal1(n,a,b,j);cal2(n,a,c,j);}
                              ^
/in/foo.c:25:30: note: each undeclared identifier is reported only once for each function it appears in