제출 #1288663

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1288663		lightentheshadow	동기화 (JOI13_synchronization)	C++20	100 / 100	249 ms	22216 KiB

synchronization

#include <bits/stdc++.h>
using namespace std;

const int maxN = 1e5 + 5;
vector<int> adj[maxN];
int in[maxN], out[maxN], par[20][maxN], timeDfs = 0;
int ans[maxN], save[maxN], status[maxN];
pair<int, int> edge[maxN];

void preDfs(int u, int pre) {
    in[u] = ++timeDfs;
    for (auto v: adj[u]) {
        if (v == pre) continue;
        par[0][v] = u;
        preDfs(v, u);
    }
    out[u] = timeDfs;
}

int BIT[maxN];
void update(int u, int v, int n) {
    int idx = u;
    while (idx <= n) {
        BIT[idx] += v;
        idx += (idx & (-idx));
    }
}

int getSum(int p) {
    int idx = p, ans = 0;
    while (idx > 0) {
        ans += BIT[idx];
        idx -= (idx & (-idx));
    }
    return ans;
}

int jump_to(int x) {
    for (int k = 16; k >= 0; k--) {
        if (!par[k][x]) continue;
        if (getSum(in[x]) - getSum(in[par[k][x]]) == (1 << k)) x = par[k][x];
    }
    return x;
}

int main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int n, m, q;
    cin >> n >> m >> q;

    for (int i = 1; i < n; i++) {
        int u, v;
        cin >> u >> v;

        adj[u].push_back(v);
        adj[v].push_back(u);
        edge[i] = {u, v};
    }

    preDfs(1, 1);
    for (int i = 1; i < n; i++)
        if (in[edge[i].first] > in[edge[i].second]) swap(edge[i].first, edge[i].second);

    for (int k = 1; k <= 16; k++)
        for (int i = 1; i <= n; i++)
            par[k][i] = par[k - 1][par[k - 1][i]];

    for (int i = 1; i <= n; i++)
        ans[i] = 1;

    while (m--) {
        int id; cin >> id;
        auto [u, v] = edge[id];

        if (!status[id]) {
            update(in[v], 1, n); update(out[v] + 1, -1, n);
            int x = jump_to(v);
            ans[x] += ans[v] - save[id];
        }
        else {
            int x = jump_to(v);
            save[id] = ans[v] = ans[x];
            update(in[v], -1, n); update(out[v] + 1, 1, n);
        }
        status[id] ^= 1;
    }

    while (q--) {
        int x; cin >> x;
        cout << ans[jump_to(x)] << '\n';
    }

    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 10 / 10
• Subtask 4: 20 / 20
• Subtask 5: 40 / 40