#1192101 (C++23(gcc16)) No.3756 Udon Network

• 問題: No.3756 Udon Network
• ユーザー: detteiuu
• 提出日時: 2026-10-09 20:54:20
• 言語: C++23(gcc16) (gcc 16.1.0 + boost 1.92.0 + ACL)
• 結果: AC
• 実行時間: 404 ms / 2,000 ms
• コード長: 8,057 bytes
• コンパイル時間: 5,732 ms
• コンパイル使用メモリ: 412,004 KB
• 実行使用メモリ: 115,928 KB
• 最終ジャッジ日時: 2026-10-09 20:55:26
• 合計ジャッジ時間: 22,936 ms
• ジャッジサーバーID （参考情報）: judge4_0 / judge3_0

サブタスク	配点	結果
Example	0 %	AC * 8
Subtask $1$	2 %	AC * 15
Subtask $2$	4 %	AC * 22
Subtask $3$	8 %	AC * 9
Subtask $4$	16 %	AC * 10
Subtask $5$	32 %	AC * 10
Subtask $6$	38 %	AC * 53
合計	4 * 100% = 400 点

ソースコード

#ifndef ONLINE_JUDGE
#define _GLIBCXX_DEBUG
#endif
#include <bits/stdc++.h>
using namespace std;

#define pass (void)0
#define INF (1<<30)-1
#define INFLL (1LL<<60)-1
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--)
#define rep2(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define repr2(i, a, b) for (int i = (int)(b) - 1; i >= (int)(a); i--)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) ((int)(x).size())
#define YesNo(cond) cout << ((cond) ? "Yes\n" : "No\n")
#define YESNO(cond) cout << ((cond) ? "YES\n" : "NO\n")

using ll = long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvi = vector<vi>;
using vvl = vector<vl>;

template <typename T> void print(const T& value) { cout << value << "\n"; }
template <typename T> void print(const vector<T>& vec) { for (auto& v : vec) cout << v << " "; cout << "\n"; }
template <typename T> void input(vector<T>& vec) { for (auto& v : vec) cin >> v; };
template <typename T> bool chmin(T& a, const T& b) { if (a > b) { a = b; return true; } return false; }
template <typename T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } return false; }

#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using vm = vector<mint>;

template <typename T>
struct UnionFindValue {
    int n;
    vector<int> parent_size;  // 負ならサイズ、正なら親
    vector<T> A;              // 各リーダーが持つ値

    UnionFindValue(int n, const vector<T>& A_) 
        : n(n), parent_size(n, -1), A(A_) {}

    int leader(int a) {
        if (parent_size[a] < 0) return a;
        return parent_size[a] = leader(parent_size[a]);
    }

    void merge(int a, int b) {
        a = leader(a);
        b = leader(b);
        if (a == b) return;

        T c = A[a];
        
        // union by size
        if (-parent_size[a] < -parent_size[b]) swap(a, b);

        // a が大きい側
        parent_size[a] += parent_size[b];
        parent_size[b] = a;

        A[a] = c;
    }

    // A[x] を取得
    T operator[](int x) {
        return A[leader(x)];
    }

    // 値を上書き
    void update(int x, T v) {
        A[leader(x)] = v;
    }

    bool same(int a, int b) {
        return leader(a) == leader(b);
    }

    int size(int x) {
        return -parent_size[leader(x)];
    }

    vector<vector<int>> groups() {
        vector<vector<int>> res(n);
        for (int i = 0; i < n; i++) {
            res[leader(i)].push_back(i);
        }
        vector<vector<int>> ans;
        for (auto &g : res) {
            if (!g.empty()) ans.push_back(g);
        }
        return ans;
    }
};

vvi G;
vl IN, OUT;
vl order;

ll dfs(ll n, ll p, ll time) {
    IN[n] = time;
    order.push_back(n);
    for (auto v : G[n]) {
        if (v == p) continue;
        time = dfs(v, n, time+1);
    }
    OUT[n] = time;
    return time;
}

vl C;

struct LCA {
    int V;
    int LOG;
    vector<vector<int>> parent;
    vector<int> depth;

    LCA(const vector<vector<int>>& G, int root = 0) {
        V = (int)G.size();
        LOG = 1;
        while ((1 << LOG) < V) LOG++;

        parent.assign(LOG, vector<int>(V, -1));
        depth.assign(V, -1);

        bfs(G, root);

        for (int i = 0; i + 1 < LOG; i++) {
            for (int v = 0; v < V; v++) {
                if (parent[i][v] != -1) {
                    parent[i + 1][v] = parent[i][ parent[i][v] ];
                }
            }
        }
    }

    void bfs(const vector<vector<int>>& G, int root) {
        queue<int> q;
        depth[root] = 0;
        q.push(root);

        while (!q.empty()) {
            int u = q.front(); q.pop();
            for (int v : G[u]) {
                if (depth[v] == -1) {
                    depth[v] = depth[u] + 1;
                    parent[0][v] = u;
                    q.push(v);
                }
            }
        }
    }

    int lca(int a, int b) const {
        if (depth[a] < depth[b]) swap(a, b);

        int diff = depth[a] - depth[b];
        for (int i = 0; i < LOG; i++) {
            if (diff & (1 << i)) {
                a = parent[i][a];
            }
        }

        if (a == b) return a;

        for (int i = LOG - 1; i >= 0; i--) {
            if (parent[i][a] != parent[i][b]) {
                a = parent[i][a];
                b = parent[i][b];
            }
        }
        return parent[0][a];
    }

    int solve(int n, int x) {
        if (x == 1) return n;
        repr (i, LOG) {
            if (parent[i][n] != -1 && C[parent[i][n]] < x) {
                n = parent[i][n];
            }
        }
        if (parent[0][n] != -1) {
            return parent[0][n];
        } else {
            return -1;
        }
    }

    int dist(int a, int b) const {
        int c = lca(a, b);
        return depth[a] + depth[b] - 2 * depth[c];
    }

    bool is_ancestor(int u, int v) const {
        return lca(u, v) == u;
    }

    int kth_ancestor(int v, int k) const {
        for (int i = 0; i < LOG; i++) {
            if (k & (1 << i)) {
                v = parent[i][v];
                if (v == -1) break;
            }
        }
        return v;
    }

    int jump(int u, int v) const {
        if (u == v) return u;
        int c = lca(u, v);
        if (c == u) {
            return kth_ancestor(v, dist(u, v) - 1);
        } else {
            return parent[0][u];
        }
    }

    int jump_k(int u, int v, int k) const {
        int d = dist(u, v);
        if (d <= k) return v;

        int c = lca(u, v);
        int du = depth[u] - depth[c];

        if (k <= du) {
            return kth_ancestor(u, k);
        } else {
            return kth_ancestor(v, d - k);
        }
    }

    bool on_path(int u, int v, int x) const {
        return dist(u, x) + dist(x, v) == dist(u, v);
    }

    pair<int,int> create_path(int u, int v, int x) const {
        if (on_path(u, v, x)) return {u, v};
        if (on_path(u, x, v)) return {u, x};
        if (on_path(v, x, u)) return {v, x};
        return {-1, -1};
    }
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(10);

    ll N, M, Q;
    cin >> N >> M >> Q;
    vl A(N); input(A);
    vector<tuple<ll, ll, ll>> edge;
    rep (_, M) {
        ll u, v, w; cin >> u >> v >> w;
        u --; v --;
        edge.push_back({w, u, v});
    }
    vector<pll> query;
    rep (_, Q) {
        ll s, c; cin >> s >> c;
        s --;
        query.push_back({s, c});
    }

    sort(all(edge));
    vector<ll> def(N);
    rep (i, N) def[i] = i;
    UnionFindValue<ll> UF(N, def);
    ll cnt = N;
    G.assign(N*2-1, vi());
    vl D(N, 0);
    for (auto [w, u, v] : edge) {
        if (UF.same(u, v)) continue;
        auto a = UF[u];
        auto b = UF[v];
        G[a].push_back(cnt);
        G[cnt].push_back(a);
        G[b].push_back(cnt);
        G[cnt].push_back(b);
        D.push_back(w);
        UF.merge(u, v);
        UF.update(u, cnt);
        cnt++;
    }

    IN.assign(N*2-1, -1); OUT.assign(N*2-1, -1);
    dfs(N*2-2, -1, 0);

    rep (i, N) A[i]--;
    rep (_, N-1) A.push_back(N);
    vl IDX(N+1, -1);
    vector<tuple<ll, ll, ll>> interval;
    rep (i, N*2-1) {
        interval.push_back({OUT[i], IN[i], i});
    }
    sort(all(interval));
    C.assign(N*2-1, -1);
    fenwick_tree<ll> B(N*2-1);
    ll idx = 0;
    rep (i, N*2-1) {
        auto now = A[order[i]];
        if (IDX[now] != -1) {
            B.add(IDX[now], -1);
        }
        IDX[now] = i;
        B.add(i, 1);
        while (idx < N*2-1 && get<0>(interval[idx]) == i) {
            auto [r, l, qidx] = interval[idx];
            C[qidx] = B.sum(l, r+1);
            if (N <= qidx) C[qidx]--;
            idx++;
        }
    }

    LCA lca(G, N*2-2);
    for (auto [s, c] : query) {
        auto idx = lca.solve(s, c);
        if (idx != -1) {
            print(D[idx]);
        } else {
            print(-1);
        }
    }
}