/in/foo.c: In function 'main':
/in/foo.c:8:7: error: 'i' undeclared (first use in this function)
    8 |   if (i=1;i<=n;i++){
      |       ^
/in/foo.c:8:7: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:8:10: error: expected ')' before ';' token
    8 |   if (i=1;i<=n;i++){
      |      ~   ^
      |          )
/in/foo.c:9:3: error: 'factional' undeclared (first use in this function); did you mean 'factorial'?
    9 |   factional*=i;
      |   ^~~~~~~~~
      |   factorial