Submission #619801

#	Time	Username	Problem	Language	Result	Execution time	Memory
619801		yuto1115	Inside information (BOI21_servers)	C++17	52.50 / 100	244 ms	37904 KiB

servers

#include <bits/stdc++.h>
#define rep(i, n) for(ll i = 0; i < ll(n); ++i)
#define rep2(i, s, n) for(ll i = ll(s); i < ll(n); ++i)
#define rrep(i, n) for(ll i = ll(n) - 1; i >= 0; --i)
#define rrep2(i, n, t) for(ll i = ll(n) - 1; i >= ll(t); --i)
#define pb push_back
#define eb emplace_back
#define all(a) a.begin(), a.end()
#define SZ(a) int(a.size())
using namespace std;
using ll = long long;
using P = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vp = vector<P>;
using vvp = vector<vp>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vs = vector<string>;
const int inf = 1001001001;
const ll linf = 1001001001001001001;

template<class T>
bool chmin(T &a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
bool chmax(T &a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int n, q;
    cin >> n >> q;
    vvp G(n);
    vp es;
    vector qs(n, vector<tuple<int, int, int>>());
    bool uni = true;
    bool line = true;
    rep(_, n + q - 1) {
        char c;
        cin >> c;
        if (c == 'S') {
            int a, b;
            cin >> a >> b;
            --a, --b;
            G[a].eb(b, SZ(es));
            G[b].eb(a, SZ(es));
            es.eb(a, b);
            uni &= (!a or !b);
            line &= abs(a - b) == 1;
        } else if (c == 'Q') {
            int a, d;
            cin >> a >> d;
            --a, --d;
            qs[SZ(es)].eb(0, d, a);
        } else {
            int d;
            cin >> d;
            --d;
            qs[SZ(es)].eb(1, d, 0);
        }
    }
    vi dep(n);
    vvi par(20, vi(n));
    vi pid(n), inc(n), dec(n);
    auto dfs = [&](auto &dfs, int u, int p, int d, int _pid) -> void {
        dep[u] = d;
        par[0][u] = p;
        pid[u] = _pid;
        for (auto[v, id]: G[u]) {
            if (v == p) continue;
            inc[v] = (u and _pid > id ? inc[u] : 0) + 1;
            dec[v] = (u and _pid < id ? dec[u] : 0) + 1;
            dfs(dfs, v, u, d + 1, id);
        }
    };
    dfs(dfs, 0, -1, 0, -1);
    rep(k, 19) {
        rep(i, n) {
            if (par[k][i] == -1) par[k + 1][i] = -1;
            else par[k + 1][i] = par[k][par[k][i]];
        }
    }
    auto la = [&](int u, int d) {
        if (!d) return u;
        rep(k, 20) {
            if (d >> k & 1) {
                u = par[k][u];
                assert(u != -1);
            }
        }
        return u;
    };
    auto lca = [&](int u, int v) {
        if (dep[u] > dep[v]) swap(u, v);
        v = la(v, dep[v] - dep[u]);
        if (u == v) return u;
        rrep(k, 20) {
            if (par[k][u] != par[k][v]) {
                u = par[k][u];
                v = par[k][v];
            }
        }
        return par[0][u];
    };
    vs ans(q);
    int it = 0;
    rep(i, n) {
        for (auto[t, d, a]: qs[i]) {
            if (t == 0) {
                int l = lca(d, a);
                int hd = dep[d] - dep[l];
                int ha = dep[a] - dep[l];
                int when;
                if (d == a) {
                    when = -1;
                } else if (l == d) {
                    when = (dec[a] >= ha ? pid[a] : inf);
                } else if (l == a) {
                    when = (inc[d] >= hd ? pid[la(d, hd - 1)] : inf);
                } else {
                    // d -> (edge : x) -> l -> (edge : y) -> a
                    int x = pid[la(d, hd - 1)];
                    int y = pid[la(a, ha - 1)];
                    when = (inc[d] >= hd and dec[a] >= ha and x < y ? pid[a] : inf);
                }
                ans[it] = (when < i ? "yes" : "no");
            } else {
                int val;
                if (uni) {
                    if (!d) {
                        val = i + 1;
                    } else {
                        val = max<int>(1, i - pid[d] + 1);
                    }
                } else if (line) {
                    val = 1;
                    val += d + 1 - (upper_bound(pid.begin() + d - inc[d] + 1, pid.begin() + d + 1, i,
                                                [&](int key, int now) { return pid[now] < key; }) - pid.begin());
                    int _d = d;
                    val += (lower_bound(pid.begin() + d + 1, pid.end(), i,
                                        [&](int now, int key) {
                                            return pid[now] < key and dec[now] >= now - _d;
                                        }) - pid.begin()) - d - 1;
                }
                ans[it] = to_string(val);
            }
            ++it;
        }
    }
    rep(i, q) cout << ans[i] << '\n';
}

//4 4
//S 1 2
//S 1 3
//S 3 4
//Q 2 1
//Q 2 2
//Q 2 3
//Q 2 4

• Subtask 1: 2.5 / 2.5
• Subtask 2: 0 / 2.5
• Subtask 3: 2.5 / 2.5
• Subtask 4: 2.5 / 2.5
• Subtask 5: 5 / 5
• Subtask 6: 0 / 5
• Subtask 7: 10 / 10
• Subtask 8: 0 / 10
• Subtask 9: 12.5 / 12.5
• Subtask 10: 0 / 12.5
• Subtask 11: 17.5 / 17.5
• Subtask 12: 0 / 17.5