/in/foo.cc: In function 'int main()':
/in/foo.cc:10:10: error: expected ';' before '*' token
  n!=1*2*3*...*n;
          ^
/in/foo.cc:10:3: warning: statement has no effect [-Wunused-value]
  n!=1*2*3*...*n;
  ~^~~~~~~
/in/foo.cc:11:5: error: expected ';' before '!' token
  C=n!/[m!*(n-m)!];
     ^