Submission #779531

#	Time	Username	Problem	Language	Result	Execution time	Memory
779531		ThegeekKnight16	Dynamic Diameter (CEOI19_diameter)	C++17	100 / 100	378 ms	62648 KiB

diameter

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int INF = 0x3f3f3f3f;
struct node
{
    int Mi, Mj, Mk, Mij, Mjk, Mijk;
    int lz;

    node(int I = 0, int J = 0, int K = 0, int IJ = 0, int JK = 0, int IJK = 0, int LZ = 0) : Mi(I), Mj(J), Mk(K), Mij(IJ), Mjk(JK), Mijk(IJK), lz(LZ) {}

    node operator+(node outro)
    {
        node resp;
        resp.Mi = resp.Mk = max(Mi, outro.Mi);
        resp.Mj = min(Mj, outro.Mj);
        resp.Mij = max({Mij, Mi - 2*outro.Mj, outro.Mij});
        resp.Mjk = max({Mjk, -2*Mj + outro.Mk, outro.Mjk});
        resp.Mijk = max({Mijk, Mij + outro.Mk, Mi + outro.Mjk, outro.Mijk});
        return resp;
    }
};
const int MAXN = 2e5 + 10;
array<node, 4*MAXN> seg;
array<vector<pair<int, int>>, MAXN> grafo;
array<int, MAXN> peso, idIn, idOut;
int temp = 0;

void refresh(int pos, int ini, int fim)
{
    if (seg[pos].lz == 0) return;
    int x = seg[pos].lz; seg[pos].lz = 0;
    seg[pos].Mi += x; seg[pos].Mj += x; seg[pos].Mk += x;
    seg[pos].Mij -= x; seg[pos].Mjk -= x;
    seg[pos].Mijk += 0;

    if (ini == fim) return;
    int e = 2*pos; int d = 2*pos + 1;
    seg[e].lz += x;
    seg[d].lz += x;
}

void update(int pos, int ini, int fim, int p, int q, int val)
{
    refresh(pos, ini, fim);
    if (q < ini || p > fim) return;
    if (p <= ini && fim <= q)
    {
        seg[pos].lz += val;
        refresh(pos, ini, fim);
        return;
    }
    int m = (ini + fim) >> 1;
    int e = 2*pos; int d = 2*pos + 1;
    update(e, ini, m, p, q, val);
    update(d, m+1, fim, p, q, val);
    seg[pos] = seg[e] + seg[d];
}

node query(int pos, int ini, int fim, int p, int q)
{
    refresh(pos, ini, fim);
    if (q < ini || p > fim) return node(-INF, INF, -INF, -INF, -INF, -INF);
    if (p <= ini && fim <= q) return seg[pos];
    int m = (ini + fim) >> 1;
    int e = 2*pos; int d = 2*pos + 1;
    return (query(e, ini, m, p, q) + query(d, m+1, fim, p, q));
}

void dfs(int v, int p, int paiEdge)
{
    ++temp;
    if (paiEdge != -1) idIn[paiEdge] = temp;

    for (auto [viz, e] : grafo[v])
    {
        if (viz == p) continue;
        dfs(viz, v, e);
    }

    ++temp;
    if (paiEdge != -1) idOut[paiEdge] = temp;
}

int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int N, Q, W;
    cin >> N >> Q >> W;
    for (int i = 1; i < N; i++)
    {
        int X, Y, P;
        cin >> X >> Y >> P;
        grafo[X].emplace_back(Y, i);
        grafo[Y].emplace_back(X, i);
        peso[i] = P;
    }
    dfs(1, 1, -1);

    --temp;
    for (int i = 1; i < N; i++) update(1, 1, temp, idIn[i], idOut[i]-1, peso[i]);

    // node aux = query(1, 1, temp, 1, temp);
    // cerr << aux.Mi << " " << aux.Mj << " " << aux.Mk << " " << aux.Mij << " " << aux.Mjk << " " << aux.Mijk << '\n';

    int last = 0;
    while (Q--)
    {
        int D, E;
        cin >> D >> E;
        D = (D + last) % (N - 1); ++D;
        E = (E + last) % W;
        update(1, 1, temp, idIn[D], idOut[D]-1, E - peso[D]);
        peso[D] = E;
        last = query(1, 1, temp, 1, temp).Mijk;
        cout << last << '\n';
    }
}

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