Submission #1046598

#	Time	Username	Problem	Language	Result	Execution time	Memory
1046598		Turkhuu	Two Currencies (JOI23_currencies)	C++17	100 / 100	743 ms	26184 KiB

currencies

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int N, M, Q, timer;
vector<int> sz, pos, dep, par, top;
vector<ll> bit;
vector<vector<int>> adj;
void add(int i, ll s) {
    for (i++; i <= N; i += i & -i) {
        bit[i] += s;
    }
}
ll sum(int i) {
    ll s = 0;
    for (; i; i -= i & -i) s += bit[i];
    return s;
}
void init(int x) {
    sz[x] = 1;
    for (auto &y : adj[x]) {
        adj[y].erase(find(adj[y].begin(), adj[y].end(), par[y] = x));
        dep[y] = dep[x] + 1;
        init(y);
        sz[x] += sz[y];
        if (sz[y] > sz[adj[x][0]]) swap(y, adj[x][0]);
    }
}
void dfs(int x) {
    pos[x] = timer++;
    for (auto y : adj[x]) {
        top[y] = y == adj[x][0] ? top[x] : y; 
        dfs(y);
    }
}
ll path(int x, int y) {
    ll s = 0;
    for (; top[x] != top[y]; x = par[top[x]]) {
        if (dep[top[x]] < dep[top[y]]) swap(x, y);
        s += sum(pos[x] + 1) - sum(pos[top[x]]);
    }
    if (dep[x] > dep[y]) swap(x, y);
    return s += sum(pos[y] + 1) - sum(pos[x] + 1);
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> N >> M >> Q;
    sz.resize(N);
    pos.resize(N);
    dep.resize(N);
    adj.resize(N);
    top.resize(N);
    par.resize(N, -1);
    bit.resize(N + 1);
    vector<pair<int, int>> edges(N - 1);
    for (int i = 0; i < N - 1; i++) {
        int a, b;
        cin >> a >> b;
        a--, b--;
        edges[i] = {a, b};
        adj[a].push_back(i);
        adj[b].push_back(i);
    }
    vector<int> w(N - 1); {
        function<void(int, int)> dfs = [&](int x, int p) {
            for (auto &y : adj[x]) {
                int i = y;
                auto [u, v] = edges[y];
                y = x ^ u ^ v;
                if (y == p) continue;
                w[i] = y;
                dfs(y, x);
            }
        };
        dfs(0, -1);
    }
    init(0); dfs(0);
    vector<pair<int, int>> ch(M);
    for (int i = 0; i < M; i++) {
        int e, s;
        cin >> e >> s; e--;
        ch[i] = {s, w[e]};
    }
    sort(ch.begin(), ch.end());
    vector<int> S(Q), T(Q), X(Q), ans(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]--;
    }
    vector<int> lo(Q), hi(Q, M);
    while (1) {
        bool end = 1;
        vector<vector<int>> v(M + 1);
        for (int i = 0; i < Q; i++) {
            if (lo[i] < hi[i]) {
                end = 0;
                v[(lo[i] + hi[i] + 1) / 2].push_back(i);
            }
        }
        if (end) break;
        bit.assign(N + 1, 0);
        for (int i = 0; i <= M; i++) {
            for (auto j : v[i]) {
                path(S[j], T[j]) <= Y[j] ? lo[j] = i : hi[j] = i - 1;
            }
            if (i < M) {
                auto [s, j] = ch[i];
                add(pos[j], s);
            }
        }
    }
    vector<vector<int>> a(M + 1);
    for (int i = 0; i < Q; i++) {
        a[lo[i]].push_back(i);
    }
    bit.assign(N + 1, 0);
    for (int i = M; i >= 0; i--) {
        if (i < M) {
            auto [s, j] = ch[i];
            add(pos[j], 1);
        }
        for (auto j : a[i]) {
            ans[j] = max<ll>(-1, X[j] - path(S[j], T[j]));
        }
    }
    for (int i = 0; i < Q; i++) cout << ans[i] << "\n";
    return 6/22;
}

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