Submission #825622

#	Time	Username	Problem	Language	Result	Execution time	Memory
825622		t6twotwo	Two Currencies (JOI23_currencies)	C++17	38 / 100	5053 ms	36812 KiB

currencies

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N, M, Q;
    cin >> N >> M >> Q;
    vector<pair<int, int>> edges(N - 1);
    vector<vector<pair<int, int>>> adj(N);
    for (int i = 0; i < N - 1; i++) {
        int x, y;
        cin >> x >> y;
        x--, y--;
        edges[i] = {x, y};
        adj[x].emplace_back(y, i);
        adj[y].emplace_back(x, i);
    }
    vector<int> P(M), C(M);
    vector<vector<int>> c(N - 1);
    for (int i = 0; i < M; i++) {
        cin >> P[i] >> C[i];
        P[i]--;
        c[P[i]].push_back(C[i]);
    }
    if (C == vector(M, C[0])) {
        vector<int> cnt(N - 1);
        for (int i = 0; i < M; i++) {
            cnt[P[i]]++;
        }
        vector<int> f(N), dep(N);
        vector par(N, vector<int>(20, -1));
        auto dfs = [&](auto dfs, int x) -> void {
            for (int i = 0; i < 19 && par[x][i] != -1; i++) {
                par[x][i + 1] = par[par[x][i]][i];
            }
            for (auto [y, z] : adj[x]) {
                if (y != par[x][0]) {
                    dep[y] = dep[x] + 1;
                    f[y] = f[x] + cnt[z];
                    par[y][0] = x;
                    dfs(dfs, y);
                }
            }
        };
        dfs(dfs, 0);
        auto lca = [&](int x, int y) {
            if (dep[x] < dep[y]) {
                swap(x, y);
            }
            for (int i = 0; i < 20; i++) {
                if ((dep[x] - dep[y]) >> i & 1) {
                    x = par[x][i];
                }
            }
            if (x == y) {
                return x;
            }
            for (int i = 19; i >= 0; i--) {
                if (par[x][i] != par[y][i]) {
                    x = par[x][i];
                    y = par[y][i];
                }
            }
            return par[x][0];
        };
        while (Q--) {
            int S, T, X; ll Y;
            cin >> S >> T >> X >> Y;
            S--, T--;
            int k = f[S] + f[T] - 2 * f[lca(S, T)];
            cout << max(-1LL, X - max(0LL, k - Y / C[0])) << "\n";
        }
        return 0;
    }
    while (Q--) {
        int S, T, X; ll Y;
        cin >> S >> T >> X >> Y;
        S--, T--;
        vector<int> p(N, -1);
        queue<int> q;
        p[S] = S;
        q.push(S);
        while (!q.empty()) {
            int x = q.front();
            q.pop();
            for (auto [y, z] : adj[x]) {
                if (p[y] == -1) {
                    p[y] = z;
                    q.push(y);
                }
            }
        }
        priority_queue<int, vector<int>, greater<int>> pq;
        while (T != S) {
            for (int v : c[p[T]]) {
                pq.push(v);
            }
            auto [x, y] = edges[p[T]];
            T ^= x ^ y;
        }
        while (!pq.empty() && pq.top() <= Y) {
            Y -= pq.top();
            pq.pop();
        }
        X -= pq.size();
        X = max(X, -1);
        cout << X << "\n";
    }
    return 6/22;
}

• Subtask 1: 10 / 10
• Subtask 2: 28 / 28
• Subtask 3: 0 / 30
• Subtask 4: 0 / 32