QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#641290#8720. BFS 序 0neetmanWA 117ms35936kbC++143.0kb2024-10-14 19:40:482024-10-14 19:40:48

Judging History

你现在查看的是最新测评结果

  • [2024-10-14 19:40:48]
  • 评测
  • 测评结果:WA
  • 用时:117ms
  • 内存:35936kb
  • [2024-10-14 19:40:48]
  • 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]];
            if(vis[sta[i]])
                jud = 0;
            vis[sta[i]] = 1;
        }
        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]){
                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
*/

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 2ms
memory: 9864kb

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: 117ms
memory: 35936kb

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:

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

result:

wrong answer expected YES, found NO [2nd token]