/in/foo.cc: In constructor 'BIGNUM::BIGNUM()':
/in/foo.cc:11:21: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
         flag = s[0] = 1;
                ~~~~~^~~
/in/foo.cc: In function 'std::ostream& operator<<(std::ostream&, const BIGNUM&)':
/in/foo.cc:178:29: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
     printf("%d", a.s[a.s[0]]);
                             ^
/in/foo.cc:180:30: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
         printf("%09d", a.s[i]);
                              ^