/in/foo.cc:14:1: error: 'bitset' does not name a type
   14 | bitset <20> tmp1, tmp2;
      | ^~~~~~
/in/foo.cc:15:11: error: 'N' was not declared in this scope
   15 | bool flag[N], b[N];
      |           ^
/in/foo.cc:15:17: error: 'N' was not declared in this scope
   15 | bool flag[N], b[N];
      |                 ^
/in/foo.cc:19:5: error: 'bitset' does not name a type
   19 |     bitset <20> dog;
      |     ^~~~~~
/in/foo.cc: In function 'void spfa(int)':
/in/foo.cc:43:13: error: 'tmp1' was not declared in this scope
   43 |             tmp1(chg);
      |             ^~~~
/in/foo.cc:42:42: warning: unused variable 'cnt' [-Wunused-variable]
   42 |                         int chg = t ^ i, cnt = 0, f = 1, temp = i;
      |                                          ^~~
/in/foo.cc:42:51: warning: unused variable 'f' [-Wunused-variable]
   42 |                         int chg = t ^ i, cnt = 0, f = 1, temp = i;
      |                                                   ^
/in/foo.cc:42:58: warning: unused variable 'temp' [-Wunused-variable]
   42 |                         int chg = t ^ i, cnt = 0, f = 1, temp = i;
      |                                                          ^~~~