Submission #825957

#	Time	Username	Problem	Language	Result	Execution time	Memory
825957		t6twotwo	Two Currencies (JOI23_currencies)	C++17	10 / 100	5077 ms	37448 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<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].push_back(i);
        adj[y].push_back(i);
    }
    vector<pair<int, int>> ch(M);
    for (int i = 0; i < M; i++) {
        int p, c;
        cin >> p >> c;
        ch[i] = {c, p - 1};
    }
    sort(ch.begin(), ch.end());
    vector<int> t(N - 1);
    {
        auto dfs = [&](auto dfs, int x, int p) -> void {
            for (int z : adj[x]) {
                auto [u, v] = edges[z];
                int y = x ^ u ^ v;
                if (y != p) {
                    t[z] = y;
                    dfs(dfs, y, x);
                }
            }
        };
        dfs(dfs, 0, -1);
    }
    for (int i = 0; i < N; i++) {
        for (int &j : adj[i]) {
            auto [x, y] = edges[j];
            j = i ^ x ^ y;
        }
    }
    vector par(N, vector<int>(20, -1));
    vector<int> dep(N), sz(N);
    auto init = [&](auto init, int x) -> void {
        for (int i = 0; i < 19 && par[x][i] != -1; i++) {
            par[x][i + 1] = par[par[x][i]][i];
        }
        if (par[x][0] != -1) {
            adj[x].erase(find(adj[x].begin(), adj[x].end(), par[x][0]));
        }
        sz[x] = 1;
        for (int &y : adj[x]) {
            par[y][0] = x;
            dep[y] = dep[x] + 1;
            init(init, y);
            sz[x] += sz[y];
            if (sz[y] > sz[adj[x][0]]) {
                swap(y, adj[x][0]);
            }
        }
    };
    init(init, 0);
    vector<int> top(N), in(N);
    int timer = 0;
    auto dfs = [&](auto dfs, int x) -> void {
        in[x] = timer++;
        for (int y : adj[x]) {
            top[y] = adj[x][0] == y ? top[x] : y;
            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];
    };
    vector<int> S(Q), T(Q), X(Q);
    vector<ll> Y(Q);
    for (int i = 0; i < Q; i++) {
        cin >> S[i] >> T[i] >> X[i] >> Y[i];
        S[i]--, T[i]--;
        if (S[i] > T[i]) {
            swap(S[i], T[i]);
        }
    }
    vector<int> lo(Q), hi(Q, M);
    vector<ll> bit(N);
    auto add = [&](int i, int v) {
        for (i++; i < N; i += i & -i) {
            bit[i] += v;
        }
    };
    auto sum = [&](int i) {
        ll s = 0;
        for (; i; i -= i & -i) {
            s += bit[i];
        }
        return s;
    };
    vector<ll> s(N);
    auto get = [&](int S, int T) {
        ll ans = 0;
        int P = lca(S, T);
        while (S != P) {
            ans += s[S];
            S = par[S][0];
        }
        while (T != P) {
            ans += s[T];
            T = par[T][0];
        }
        return ans;
    };
    for (int z = 0; z < 20; z++) {
        vector<int> mi(Q);
        vector<vector<int>> f(M);
        for (int i = 0; i < Q; i++) {
            if (lo[i] != hi[i]) {
                mi[i] = (lo[i] + hi[i] + 1) / 2;
                f[mi[i] - 1].push_back(i);
            }
        }
        s.assign(N, 0);
        for (int i = 0; i < M; i++) {
            auto [c, p] = ch[i];
            s[t[p]] += c;
            for (int j : f[i]) {
                if (get(S[j], T[j]) <= Y[j]) {
                    lo[j] = i + 1;
                } else {
                    hi[j] = i;
                }
            }
        }
    }
    vector<ll> ans(Q);
    vector<vector<int>> f(M + 1);
    for (int i = 0; i < Q; i++) {
        f[lo[i]].push_back(i);
    }
    s.assign(N, 0);
    for (int i = M; i >= 0; i--) {
        if (i < M) {
            auto [c, p] = ch[i];
            s[t[p]]++;
        }
        for (int j : f[i]) {
            ans[j] = max(-1LL, X[j] - get(S[j], T[j]));
        }
    }
    for (int i = 0; i < Q; i++) {
        cout << ans[i] << "\n";
    }
    return 6/22;
}

Compilation message (stderr)

currencies.cpp: In function 'int main()':
currencies.cpp:108:10: warning: variable 'add' set but not used [-Wunused-but-set-variable]
  108 |     auto add = [&](int i, int v) {
      |          ^~~
currencies.cpp:113:10: warning: variable 'sum' set but not used [-Wunused-but-set-variable]
  113 |     auto sum = [&](int i) {
      |          ^~~

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