/in/foo.cc: In function 'void mk_tree(int)':
/in/foo.cc:28:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |     for (int i = 0; i < conn[node].size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'void prepare(int)':
/in/foo.cc:38:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |     for (int i = 0; i < tree[node].size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'void calc(int)':
/in/foo.cc:54:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |     for (int i = 0; i < tree[node].size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:81:17: warning: format '%d' expects argument of type 'int', but argument 3 has type 'long long int' [-Wformat=]
   81 |     printf("%d %d", g[1], (2*f[1])%MOD);
      |                ~^         ~~~~~~~~~~~~
      |                 |                 |
      |                 int               long long int
      |                %lld