제출 #1248653

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1248653		_callmelucian	동기화 (JOI13_synchronization)	C++17	100 / 100	77 ms	16456 KiB

synchronization

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

using ll = long long;
using ld = long double;
using pl = pair<ll,ll>;
using pii = pair<int,int>;
using tpl = tuple<int,int,int>;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

const int mn = 1e5 + 5;
int chain[mn], sz[mn], par[mn], num[mn], tail[mn], synchron[mn], passed[mn], timeDfs;
bool stop[mn], toParent[mn], state[2 * mn];
vector<int> adj[mn];
pii edge[mn];

struct BIT {
    vector<int> tr;
    BIT (int sz) : tr(sz + 1) {}

    int p (int k) { return k & -k; }

    void upd (int k, int val) {
        for (; k < tr.size(); k += p(k)) tr[k] += val;
    }

    void update (int l, int r, int val) { upd(l, val), upd(r + 1, -val); }

    int get (int k, int ans = 0) {
        for (; k; k -= p(k)) ans += tr[k];
        return ans;
    }
} tree(mn);

int szDfs (int u, int p) {
    sz[u] = 1;
    for (int v : adj[u])
        if (v != p) sz[u] += szDfs(v, u);
    return sz[u];
}

void dfs (int u, int p, int d, bool toP) {
    if (u == 1) szDfs(u, p);
    num[u] = ++timeDfs, par[u] = p;
    chain[u] = (toP ? chain[p] : u);

    if (adj[u].empty()) return;
    int heavy = *max_element(all(adj[u]), [&] (int a, int b) {
                    return (a == p ? INT_MIN : sz[a]) < (b == p ? INT_MIN : sz[b]);
                });
    if (heavy != p) dfs(heavy, u, d + 1, 1);
    for (int v : adj[u])
        if (v != p && v != heavy) dfs(v, u, d + 1, 0);
}

int getRoot (int u) {
    while (!stop[u] || toParent[u]) {
//        cout << stop[u] << " " << u << endl;
        if (toParent[u]) u = par[u];
        else u = tree.get(num[u]);
    }
    return u;
}


void disconnect (int u, int v) {
    if (chain[u] != chain[v]) toParent[v] = 0;
    else {
        int t = tree.get(num[u]);
        tree.update(num[v], tail[t], v - t);
        tail[v] = tail[t], tail[t] = num[u], stop[v] = 1;
    }
}

void connect (int u, int v) {
    if (chain[u] != chain[v]) toParent[v] = 1;
    else {
        int t = tree.get(num[u]);
        tree.update(num[v], tail[v], t - v);
        tail[t] = tail[v], stop[v] = 0;
    }
}

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

    /// read input and run dfs
    int n, m, q; cin >> n >> m >> q;
    for (int i = 1; i < n; i++) {
        int a, b; cin >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
        edge[i] = {a, b};
    }
    dfs(1, 0, 1, 0);

    /// pre-process
    for (int i = 1; i < n; i++) {
        int a, b; tie(a, b) = edge[i];
        if (num[a] > num[b]) edge[i] = {b, a};
    }
    for (int i = 1; i <= n; i++) {
        synchron[i] = stop[i] = 1, tail[i] = num[i];
        tree.update(num[i], num[i], i);
    }

    /// process updates & synchronizations
    for (int i = 0; i < m; i++) {
        int d; cin >> d;
        int a, b; tie(a, b) = edge[d];
        if (state[d]) {
            synchron[b] = passed[b] = synchron[getRoot(a)];
            disconnect(a, b), state[d] = 0;
        }
        else {
            synchron[getRoot(a)] += synchron[b] - passed[b];
            connect(a, b), state[d] = 1;
        }
    }

    /// answer queries
    for (int i = 0; i < q; i++) {
        int u; cin >> u;
        cout << synchron[getRoot(u)] << " ";
    }

    return 0;
}

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