`if(dfn[t]!=1) ` 应该改为 `if(!dfn[t]) `。
by Priscilla_ism @ 2022-10-24 17:07:01
`add` 函数建议用 `void`，同时不建议 `cnt[xiayige]=head[x]` 的写法。
by Priscilla_ism @ 2022-10-24 17:08:24
@[Priscilla_ism](/user/846956) 感谢大佬，已AC
by Esawkm @ 2022-10-24 17:25:48