/in/foo.cc: In function 'void spfa(int)':
/in/foo.cc:62:42: warning: comparison of integer expressions of different signedness: 'std::size_t' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   62 |                         if (tmp1.count() <= m-1) {
      |                             ~~~~~~~~~~~~~^~~~~~
/in/foo.cc:50:42: warning: unused variable 'cnt' [-Wunused-variable]
   50 |                         int chg = t ^ i, cnt = 0, f = 1, temp = i;
      |                                          ^~~
/in/foo.cc:50:51: warning: unused variable 'f' [-Wunused-variable]
   50 |                         int chg = t ^ i, cnt = 0, f = 1, temp = i;
      |                                                   ^
/in/foo.cc:50:58: warning: unused variable 'temp' [-Wunused-variable]
   50 |                         int chg = t ^ i, cnt = 0, f = 1, temp = i;
      |                                                          ^~~~