QOJ.ac

QOJ

ID题目提交者结果用时内存语言文件大小提交时间测评时间
#641304#8720. BFS 序 0neetmanWA 100ms37844kbC++142.9kb2024-10-14 19:44:122024-10-14 19:44:13

Judging History

你现在查看的是最新测评结果

  • [2024-10-14 19:44:13]
  • 评测
  • 测评结果:WA
  • 用时:100ms
  • 内存:37844kb
  • [2024-10-14 19:44:12]
  • 提交

answer

#include<algorithm>
#include<iostream>
#include<cstdio>
using namespace std;
const int N = 3e5 + 5;
int n, m, q, tot, top;
int fa[N][20], head[N], dep[N], idx[N];
int vis[N], sta[N*2], maxn[N]; 
struct edge{
    int u, v;
}e[N];

int cnt;
void addedge(int x, int y){
    e[++cnt].u = head[x];
    e[cnt].v = y;
    head[x] = cnt;
}

void dfs(int x){
    for(int i = 1; fa[x][i] = fa[fa[x][i-1]][i-1]; i ++);
    for(int i = head[x]; i; i = e[i].u){
        int to = e[i].v;
        dep[to] = dep[x] + 1;
        dfs(to);
    }
    idx[x] = ++tot;
}

int lca(int x, int y){
    if(dep[x] != dep[y]){
        if(dep[x] < dep[y]) swap(x, y);
        for(int i = 19; ~i; i --){
            if(dep[fa[x][i]] >= dep[y])
                x = fa[x][i];
        }
    }
    if(x == y) return x;
    for(int i = 19; ~i; i --)
        if(fa[x][i] != fa[y][i]){
            x = fa[x][i];
            y = fa[y][i];
        }
    return fa[x][0];
}

int main(){
    ios::sync_with_stdio(0),cin.tie(0);
    cin >> n;
    for(int i = 2; i <= n; i ++){
        cin >> fa[i][0];
        addedge(fa[i][0], i);
    }
    dep[1] = 1;
    dfs(1);
    cin >> q;
    bool jud;
    while(q --){
        cin >> m; jud = 1;
        for(int i = 1; i <= m; i ++){
            cin >> sta[i];
            maxn[sta[i]] = dep[sta[i]];
        }
        top = m;
        // cout << "q = " << q << " jud = " << jud << '\n';
        for(int i = m - 1; i; i --){
            int LCA = lca(sta[i], sta[top]);
            // cout << "TEST!! " << sta[i] << " " << sta[top] << " " << maxn[sta[i]] << " " << maxn[sta[top]] << '\n';
            if(LCA == sta[i]){
                sta[++top] = sta[i];
                continue;
            }
            if(LCA == sta[top]){
                if(maxn[sta[top]] < maxn[sta[i]])
                    jud = 0;
                maxn[sta[top]] = maxn[sta[i]];
            }
            else{
                if(maxn[sta[top]] < maxn[sta[i]])
                    jud = 0;
                sta[++top] = LCA;
                maxn[sta[top]] = maxn[sta[i]];
            }
        }
        if(jud) cout << "Yes\n";
        else cout << "No\n";
        for(int i = 1; i <= top; i ++)
            maxn[sta[i]] = vis[sta[i]] = 0;
        // sort(sta + 1, sta + 1 + m, [](int x, int y){
        //     return idx[x] < idx[y];
        // });
        // siz = m;
        // for(int i = 1; i < m; i ++){
        //     int LCA = lca(sta[i], sta[i + 1]);
        //     if(!is[LCA]){
        //         sta[++siz] = LCA;
        //         is[LCA] = 1;
        //     }
        //     if(!nex[sta[i]])
        // }
        // for(int i = 1; i <= siz; i ++){
        //     is[sta[i]] = nex[sta[i]] = L[sta[i]] = R[sta[i]] = in[sta[i]] = 0;
        // }
    }
    return 0;
}
/*
6
1 1 3 2 4
10
4 3 6 2 5
1 4
3 2 4 5
5 2 5 4 6 3
3 1 4 2
3 5 6 3
5 4 5 2 6 1
4 4 3 2 5
4 4 6 2 3
3 3 2 6
*/

详细

Test #1:

score: 100
Accepted
time: 2ms
memory: 11756kb

input:

6
1 1 3 2 4
10
4 3 6 2 5
1 4
3 2 4 5
5 2 5 4 6 3
3 1 4 2
3 5 6 3
5 4 5 2 6 1
4 4 3 2 5
4 4 6 2 3
3 3 2 6

output:

No
Yes
Yes
No
No
No
No
No
No
Yes

result:

ok 10 token(s): yes count is 3, no count is 7

Test #2:

score: -100
Wrong Answer
time: 100ms
memory: 37844kb

input:

300000
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1...

output:

Yes
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Yes
Yes...

result:

wrong answer expected NO, found YES [1st token]