foo.cc: In function ‘int dfs(int)’:
foo.cc:11:22: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   11 |         for(int a=0;a<son[k].size();a++)
      |                     ~^~~~~~~~~~~~~~
foo.cc: In function ‘int main()’:
foo.cc:49:30: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   49 |                 for(int b=0;b<son[a].size();b++)
      |                             ~^~~~~~~~~~~~~~

正在同步测试数据，请稍后