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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#602643#8720. BFS 序 0ucup-team902#WA 194ms51916kbC++232.8kb2024-10-01 11:28:162024-10-01 11:28:18

Judging History

你现在查看的是最新测评结果

  • [2024-10-01 11:28:18]
  • 评测
  • 测评结果:WA
  • 用时:194ms
  • 内存:51916kb
  • [2024-10-01 11:28:16]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
int n;
vector<int> G[400005], G2[400005];
int fa[400005][20];
int dep[400005], b[400005];
int LCA(int u, int v) {
    if (dep[u] < dep[v]) swap(u, v);
    for (int i = 19; ~i; i--)
        if (dep[fa[u][i]] >= dep[v]) u = fa[u][i];
    if (u == v) return v;
    for (int i = 19; ~i; i--)
        if (fa[u][i] != fa[v][i]) {
            u = fa[u][i], v = fa[v][i];
        }
    return fa[u][0];
}

int dis(int u, int v) {
    return dep[u] + dep[v] - 2 * dep[LCA(u, v)];
}
int jumpfa(int u, int dis) {
    for (int i = 19; ~i; i--)
        if (dis >= (1 << i)) u = fa[u][i], dis -= (1 << i);
    return u;
}
void dfs(int u) {
    for (int i = 1; i < 20; i++) fa[u][i] = fa[fa[u][i - 1]][i - 1];
    for (int v : G[u]) {
        fa[v][0] = u;
        dep[v] = dep[u] + 1;
        dfs(v);
    }
}
int deg[400005];
bool topsort(vector<int> pt) {
    for (int x : pt) deg[x] = 0;
    for (int x : pt) {
        for (int v : G2[x]) deg[v]++;
    }
    queue<int> q;
    int cnt = 0;
    for (int x : pt) {
        if (deg[x] == 0) q.push(x);
    }
    while (!q.empty()) {
        int x = q.front();
        q.pop();
        cnt++;
        for (int v : G2[x]) {
            deg[v]--;
            if (deg[v] == 0) q.push(v);
        }
    }
    return cnt == (int)pt.size();
}
int dd[400005];
void solve() {
    cin >> n;
    for (int i = 2; i <= n; ++i) {
        int x;
        cin >> x, G[x].push_back(i);
    }
    dfs(1);
    // for (int i = 1; i <= n; ++i) cout << dep[i] << endl;
    int q;
    cin >> q;
    for (int tt = 1; tt <= q; ++tt) {
        int m;
        cin >> m;
        vector<int> a(m);
        for (int i = 0; i < m; ++i) cin >> a[i];
        bool flag = 1;
        for (int i = 1; i < m; ++i) {
            if (dep[a[i]] < dep[a[i - 1]]) flag = 0;
        }
        if (flag) {
            vector<int> vis;
            for (int i = 1; i < m; ++i) {
                int x = a[i - 1], y = a[i];
                if (dep[x] != dep[y]) continue;
                if (dd[x] == tt) flag = 0;
                dd[x] = tt;
                int Lca = LCA(x, y);
                int xx = jumpfa(x, dep[x] - dep[Lca] - 1), yy = jumpfa(y, dep[y] - dep[Lca] - 1);
                // cout << xx << " " << x << " " << yy << " " << y << " " << Lca << endl;
                G2[xx].push_back(yy);
                vis.push_back(xx);
                vis.push_back(yy);
            }
            if (dd[a[m - 1]] == tt) flag = 0;
            if (flag) flag = topsort(vis);
            for (int v : vis) G2[v].clear();
        }
        cout << (flag ? "Yes" : "No") << endl;
    }
}
int main() {
    ios::sync_with_stdio(false);
    int T = 1;
    while (T--) {
        solve();
    }
}

Details

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Test #1:

score: 100
Accepted
time: 2ms
memory: 3808kb

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: 194ms
memory: 51916kb

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

result:

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