@[TheDreamToSky](/user/1047177)
注意这句话：
>接下来 $ M $ 行，每行一个正整数 $ x $ ，表示将 $ x $ 号同学从队列中移去，如果 $ x $ 号同学已经不在队列中则忽略这一条指令。
$ code $ :
```cpp
#include <iostream>
using namespace std;
const int Nm = 1e5 + 10;
struct node
{
int pn[2];
}Node[Nm];
bool b[Nm];
int main()
{
int M, N;
scanf("%d", &N);
int first = 1;
for (int i = 2; i <= N; i++) {
int k, p; scanf("%d %d", &k, &p);
Node[Node[k].pn[p]].pn[p ^ 1] = i;
Node[i].pn[p] = Node[k].pn[p];
Node[i].pn[p ^ 1] = k;
Node[k].pn[p] = i;
if (k == first && p == 0)
first = i;
}
scanf("%d", &M);
while (M--)
{
int x; scanf("%d", &x);
if (b[x] == true)
continue;
Node[Node[x].pn[0]].pn[1] = Node[x].pn[1];
Node[Node[x].pn[1]].pn[0] = Node[x].pn[0];
if (x == first)
first = Node[x].pn[1];
b[x] = true;
}
for (int i = first; i != 0; i = Node[i].pn[1])
printf("%d ", i);
}
```
by qianhaoyu @ 2024-04-15 20:18:26
@[qianhaoyu](/user/924502) 十分感谢！
by TheDreamToSky @ 2024-04-21 09:47:07