Submission #684489

#	Time	Username	Problem	Language	Result	Execution time	Memory
684489		noedit	Bridges (APIO19_bridges)	C++17	100 / 100	2262 ms	12160 KiB

bridges

#include <bits/stdc++.h>
//#include <quadmath.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//#define sz(x) (int)x.size()
//#define sqr(x) x*x
#pragma GCC optimize("-O3")
#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.1,sse4.2,popcnt,abm,mmx,avx,avx2,tune=native")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("fast-math")
using namespace std;
//using namespace __gnu_pbds;
//
//#define int long long
////#define ld long double
//template <class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long ll;

const int MAXN = 5e4;
const int B = 1200;

struct DSU
{
    int n;
    vector<int> sz, p;
    vector<array<int, 4> > rb;
    void init(int nn)
    {
        n = nn;
        sz.resize(n, 1);
        p.resize(n);
        iota(p.begin(), p.end(), 0);
    }
    int get_par(int a)
    {
        if (p[a] == a)
             return a;
        return get_par(p[a]);
    }
    void mrg(int a, int b)
    {
        a = get_par(a);
        b = get_par(b);
        if (a != b)
        {
            if (sz[a] < sz[b])
                swap(a, b);
            rb.push_back({b, a, p[b], sz[a]});
            sz[a] += sz[b];
            p[b] = a;
        }
    }
    void rollback(int x)
    {
        while ((int)rb.size() > x)
        {
            auto&[b, a, pb, sza] = rb.back();
            rb.pop_back();
            p[b] = pb;
            sz[a] = sza;
        }
    }
};

void solve()
{
    int n, m;
    cin >> n >> m;
    vector<array<int, 3> > es(m);
    for (int i = 0; i < m; i++)
    {
        int u, v, w;
        cin >> u >> v >> w;
        u--; v--;
        es[i] = {w, u, v};
    }
    int q;
    cin >> q;
    vector<array<int, 3> > qs(q);
    for (int i = 0; i < q; i++)
    {
        int t, u, w;
        cin >> t >> u >> w;
        u--;
        qs[i] = {t, u, w};
    }
    vector<int> ans(q, -1);
    for (int i = 0; i < q; i += B)
    {
        vector<bool> active(m);
        vector<int> edges;
        auto ess = es;
        edges.reserve(B);
        vector<array<int, 4> > act;
        act.reserve(B + m);
        for (int j = i; j < min(q, i + B); j++)
        {
            auto& [t, u, w] = qs[j];
            if (t == 1)
            {
                active[u] = 1;
                ess[u][0] = w;
                edges.push_back(j);
            }
            else
            {
                act.push_back({w, 0, u, j});
            }
        }
        sort(edges.begin(), edges.end(), [&](int a, int b) {return qs[a][1] < qs[b][1] || (qs[a][1] == qs[b][1] && a < b);});
        for (int j = 0; j < m; j++)
        {
            auto& [w, u, v] = es[j];
            if (!active[j])
            {
                act.push_back({w, 1, u, v});
            }
        }
        sort(act.rbegin(), act.rend());
        DSU dsu;
        dsu.init(n);
        for (auto& [w, t, u, v] : act)
        {
            if (t == 0)
            {
                int kek = dsu.rb.size();
                for (int k  = 0; k < (int)edges.size();)
                {
                    int bebra = k;
                    int wei = -1;
                    while (bebra < (int)edges.size() && qs[edges[bebra]][1] == qs[edges[k]][1])
                    {
                        if (edges[bebra] < v)
                        {
                            wei = qs[edges[bebra]][2];
                        }
                        ++bebra;
                    }
                    int numb = qs[edges[k]][1];
                    if (wei == -1)
                    {
                        wei = es[numb][0];
                    }
                    if (w <= wei)
                    {
                        dsu.mrg(es[numb][1], es[numb][2]);
                    }
                    k = bebra;

                }
                ans[v] = dsu.sz[dsu.get_par(u)];
                dsu.rollback(kek);
            }
            else
            {
                dsu.mrg(u, v);
            }
        }
        es = ess;
    }
    for (auto& i : ans)
    {
        if (i != -1)
        cout << i << '\n';
    }
}
//
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t;
    t = 1;
    while (t--)
    {
        solve();
    }
    cerr << fixed << setprecision(3) << "Time execution: " << (double)clock() / CLOCKS_PER_SEC << endl;
    return 0;
}
//
//
///*
//4 4
//1 2 1 3
//1 1
//1 2
//1 3
//1 4
//*/

• Subtask 1: 13 / 13
• Subtask 2: 16 / 16
• Subtask 3: 17 / 17
• Subtask 4: 14 / 14
• Subtask 5: 13 / 13
• Subtask 6: 27 / 27