제출 #1326055

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1326055		nxk02102010	Dynamic Diameter (CEOI19_diameter)	C++20	49 / 100	4614 ms	46924 KiB

diameter

#include <bits/stdc++.h>
using namespace std;

const int N = 200000 + 5;
const long long INF = 1000000000000000005LL;

struct Edge {
    int u, v;
    long long w;
};

struct Node {
    long long du, dv, duw, dwv, duwv;
    Node() {
        du = INF;
        dv = -INF;
        duw = -INF;
        dwv = -INF;
        duwv = 0;
    }
};

int n, q, m;
long long W, res;
vector<pair<int,int>> adj[N];
Edge edge[N];
int in[N], out[N], ver[N], h[N];
long long d[N];
Node st[4 * N];
long long lz[4 * N];

void euler(int u, int p) {
    in[u] = ++m;
    out[u] = m;
    ver[m] = u;
    for (auto it : adj[u]) {
        int v = it.first;
        int w = it.second;
        if (v == p) continue;
        h[v] = h[u] + 1;
        d[v] = d[u] + w;
        euler(v, u);
    }
    if (p != 0) {
        out[p] = ++m;
        ver[m] = p;
    }
}

long long minimize(long long a, long long b) {
    return a < b ? a : b;
}

long long maximize(long long a, long long b) {
    return a > b ? a : b;
}

Node mergeNode(const Node &A, const Node &B) {
    Node res;
    res.du = minimize(A.du, B.du);
    res.dv = maximize(A.dv, B.dv);

    res.duw = maximize(A.duw, B.duw);
    res.duw = maximize(res.duw, A.dv - 2 * B.du);

    res.dwv = maximize(A.dwv, B.dwv);
    res.dwv = maximize(res.dwv, B.dv - 2 * A.du);

    res.duwv = maximize(A.duwv, B.duwv);
    res.duwv = maximize(res.duwv, A.duw + B.dv);
    res.duwv = maximize(res.duwv, A.dv + B.dwv);

    return res;
}

void pushDown(int id) {
    long long v = lz[id];
    if (v == 0) return;

    for (int t = 0; t < 2; t++) {
        int c = id * 2 + t;
        st[c].du += v;
        st[c].dv += v;
        st[c].duw -= v;
        st[c].dwv -= v;
        lz[c] += v;
    }
    lz[id] = 0;
}

void build(int id, int l, int r) {
    if (l == r) {
        st[id].du = d[ver[l]];
        st[id].dv = d[ver[l]];
        st[id].duw = -d[ver[l]];
        st[id].dwv = -d[ver[l]];
        st[id].duwv = 0;
        return;
    }
    int mid = (l + r) >> 1;
    build(id * 2, l, mid);
    build(id * 2 + 1, mid + 1, r);
    st[id] = mergeNode(st[id * 2], st[id * 2 + 1]);
}

void update(int id, int l, int r, int u, int v, long long x) {
    if (l > v || r < u) return;
    if (u <= l && r <= v) {
        st[id].du += x;
        st[id].dv += x;
        st[id].duw -= x;
        st[id].dwv -= x;
        lz[id] += x;
        return;
    }
    pushDown(id);
    int mid = (l + r) >> 1;
    update(id * 2, l, mid, u, v, x);
    update(id * 2 + 1, mid + 1, r, u, v, x);
    st[id] = mergeNode(st[id * 2], st[id * 2 + 1]);
}

void solve() {
    cin >> n >> q >> W;
    for (int i = 1; i < n; i++) {
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
        edge[i] = {u, v, w};
    }

    euler(1, 0);
    build(1, 1, m);

    while (q--) {
        int d_id;
        long long e;
        cin >> d_id >> e;

        d_id = (d_id + res) % (n - 1) + 1;
        e = (e + res) % W;

        int u = edge[d_id].u;
        int v = edge[d_id].v;
        int w = edge[d_id].w;
        if (h[u] > h[v]) swap(u, v);

        update(1, 1, m, in[v], out[v], e - w);
        res = st[1].duwv;
        cout << res << '\n';
        edge[d_id].w = e;
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    solve();
    return 0;
}

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 7 / 7
• Subtask 4: 18 / 18
• Subtask 5: 0 / 24
• Subtask 6: 0 / 27