View Compilation Error

0_0_34871555_7415.c:9:1: error: unknown type name 'bool'
 bool vis[maxn];
 ^
0_0_34871555_7415.c: In function 'main':
0_0_34871555_7415.c:41:2: error: expected expression before '/' token
  //freopen("in.txt", "r", stdin);
  ^
0_0_34871555_7415.c:42:2: error: expected expression before '/' token
  //freopen("out.txt", "w", stdout);
  ^