Submission #532656

#	Time	Username	Problem	Language	Result	Execution time	Memory
532656		mat50013	Dynamic Diameter (CEOI19_diameter)	C++11	24 / 100	5073 ms	150872 KiB

diameter

#include <bits/stdc++.h>

using namespace std;

using ll = long long;
const int NMAX(100005);
vector<pair<int, ll> > G[NMAX];
vector<int> frati[NMAX];
map<pair<int, int>, vector<pair<int, int> > > mp;
bool dead[NMAX], mark[NMAX], viz[NMAX];
int pas, dim, sz[NMAX], tip[NMAX], cnt, baza, mov, id[NMAX];
ll dist[NMAX], maxx[NMAX];

struct SEGTREE
{
    vector<ll> Arb, lazy;
    vector<int> in, out;
    int cati;
    inline void init(int n)
    {
        cati = n;
        int put = 1;
        while(put <= n)
            put <<= 1;
        put <<= 1;
        Arb.resize(put), in.resize(put), out.resize(put), lazy.resize(put << 1);
    }
    inline void build(int nod, int st, int dr)
    {
        if(st == dr)
        {
            Arb[nod] = dist[st];
            return;
        }
        int mij = (st + dr) / 2;
        build(2 * nod, st, mij);
        build(2 * nod + 1, mij + 1, dr);
        Arb[nod] = max(Arb[2 * nod], Arb[2 * nod + 1]);
    }
    inline void push(int nod){
        if(lazy[nod]){
            Arb[nod] += lazy[nod];
            lazy[2 * nod] += lazy[nod];
            lazy[2 * nod + 1] += lazy[nod];
            lazy[nod] = 0;
        }
    }
    inline void update(int nod, int st, int dr, int a, int b, int val){
        if(a <= st && dr <= b){
            lazy[nod] += val;
            push(nod);
            return;
        }
        push(nod);
        int mij = (st + dr) / 2;
        if(a <= mij)
            update(2 * nod, st, mij, a, b, val);
        if(b > mij)
            update(2 * nod + 1, mij + 1, dr, a, b, val);
        push(2 * nod), push(2 * nod + 1);
        Arb[nod] = max(Arb[2 * nod], Arb[2 * nod + 1]);
    }
    inline int query(int nod, int st, int dr, int a, int b){
        push(nod);
        if(a <= st && dr <= b)
            return Arb[nod];
        int mij = (st + dr) / 2;
        int rez1 = 0, rez2 = 0;
        if(a <= mij)
            rez1 = query(2 * nod, st, mij, a, b);
        if(b > mij)
            rez2 = query(2 * nod + 1, mij + 1, dr, a, b);
        return max(rez1, rez2);
    }
} interv[NMAX];

inline int getC(int nod)
{
    viz[nod] = 1;
    sz[nod] = 1;
    int maxx = 0;
    for(auto it: G[nod])
        if(!viz[it.first] && mark[it.first])
        {
            int c = getC(it.first);
            if(c != -1)
                return c;
            sz[nod] += sz[it.first];
            maxx = max(maxx, sz[it.first]);
        }
    maxx = max(maxx, dim - sz[nod]);
    if(maxx <= dim / 2)
        return nod;
    return -1;
}

inline void DFS(int nod)
{
    viz[nod] = 1;
    tip[nod] = cnt;
    for(auto it: G[nod])
        if(!viz[it.first] && mark[it.first])
            DFS(it.first);
}

inline void buildTree(int nod, int tata = -1)
{
    interv[baza].in[id[nod]] = ++mov;
    for(auto it: G[nod])
        if(tata != it.first && mark[it.first])
        {
            mp[ {min(it.first, nod), max(it.first, nod)}].push_back({id[it.first], baza});
            dist[mov + 1] = dist[interv[baza].in[id[nod]]] + it.second;
            buildTree(it.first, nod);
        }
    interv[baza].out[id[nod]] = mov;
}

inline void centroidDecomp(vector<int> nodes)
{
    if(nodes.size() == 1)
        return;
    int mr = 0;
    for(auto it: nodes)
        mark[it] = 1, sz[it] = tip[it] = 0, viz[it] = 0, id[it] = ++mr;

    dim = nodes.size();
    int cen = getC(nodes[0]);
    baza = cen;
    mov = dist[1] = 0;
    interv[baza].init(nodes.size());
    buildTree(cen);
    interv[baza].build(1, 1, nodes.size());

    for(auto it: nodes)
        viz[it] = 0;
    viz[cen] = 1;
    cnt = 0;
    for(auto it: G[cen])
        if(!viz[it.first] && mark[it.first])
        {
            frati[cen].push_back(id[it.first]);
            ++cnt;
            DFS(it.first);
        }
    vector<vector<int> > nex(cnt + 1);
    for(auto it: nodes)
        nex[tip[it]].push_back(it);

    for(auto it: nodes)
        mark[it] = 0, sz[it] = tip[it] = 0, viz[it] = 0;
    int nn = cnt;
    for(int i = 1; i <= nn; ++i)
        centroidDecomp(nex[i]);
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);

    int n, q;
    ll w;
    cin >> n >> q >> w;

    vector<tuple<int, int, int> > Muchie;
    for(int i = 1; i < n; ++i)
    {
        int a, b;
        ll c;
        cin >> a >> b >> c;
        Muchie.push_back(make_tuple(min(a, b), max(a, b), c));
        G[a].push_back({b, c});
        G[b].push_back({a, c});
    }

    vector<int> noduri;
    for(int i = 1; i <= n; ++i)
        noduri.push_back(i);
    centroidDecomp(noduri);

    auto calc = [](int i)
    {
        vector<int> vec;
        for(auto it: frati[i])
        {
            int val = interv[i].query(1, 1, interv[i].cati, interv[i].in[it], interv[i].out[it]);
            vec.push_back(val);
        }
        sort(vec.begin(), vec.end(), greater<int>());
        int maxxx = 0;
        if(vec.size() > 1)
            maxxx = vec[0] + vec[1];
        else maxxx = vec[0];
        return maxxx;
    };

    for(int i = 1; i <= n; ++i)
        if(frati[i].size())
            maxx[i] = calc(i);

    ll last = 0;
    for(int i = 1; i <= q; ++i)
    {
        int d;
        ll e;
        cin >> d >> e;
        d = (d + last) % (n - 1);
        e = (e + last) % w;

        int x, y, c;
        tie(x, y, c) = Muchie[d];
        for(auto it: mp[ {x, y}]){
            interv[it.second].update(1, 1, interv[it.second].cati, interv[it.second].in[it.first], interv[it.second].out[it.first], e - c);
            maxx[it.second] = calc(it.second);
        }
        Muchie[d] = make_tuple(x, y, e);
        ll rz = 0;
        for(int j = 1; j <= n; ++j)
            rz = max(rz, maxx[j]);
        cout << rz << '\n';
        last = rz;
    }
    return 0;
}

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