제출 #231295

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
231295		WLZ	조이터에서 친구를 만드는건 재밌어 (JOI20_joitter2)	C++14	100 / 100	1314 ms	72140 KiB

joitter2

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

int n, m;
long long ans = 0;
vector<int> p, sz;
vector< set<int> > in_v, in_group, out_group, members;
vector<long long> cost;

int root(int x) {
    if (p[x] == x) {
        return x;
    }
    return (p[x] = root(p[x]));
}

void merge(int u, int v) {
    u = root(u); v = root(v);
    if (u == v) {
        return;
    }
    ans -= (long long) members[u].size() * (long long) (members[u].size() + in_v[u].size() - 1);
    ans -= (long long) members[v].size() * (long long) (members[v].size() + in_v[v].size() - 1);
    if (members[u].size() + in_v[u].size() + in_group[u].size() + out_group[v].size() < members[v].size() + in_v[v].size() + in_group[v].size() + out_group[v].size()) {
        swap(u, v);
    }
    for (auto& x : members[v]) {
        members[u].insert(x);
        if (in_v[u].count(x)) {
            in_v[u].erase(x);
        }
    }
    members[v].clear();
    for (auto& x : in_v[v]) {
        if (!members[u].count(x)) {
            in_v[u].insert(x);
        }
    }
    in_v[v].clear();
    ans += (long long) members[u].size() * (long long) (members[u].size() + in_v[u].size() - 1);
    vector<int> to_merge;
    for (auto& x : in_group[v]) {
        if (out_group[u].count(x)) {
            to_merge.push_back(x);
        }
        out_group[x].erase(v);
        out_group[x].insert(u);
        in_group[u].insert(x);
    }
    in_group[v].clear();
    for (auto& x : out_group[v]) {
        if (in_group[u].count(x)) {
            to_merge.push_back(x);
        }
        in_group[x].erase(v);
        in_group[x].insert(u);
        out_group[u].insert(x);
    }
    out_group[v].clear();
    in_group[u].erase(v);
    out_group[u].erase(v);
    p[v] = u;
    for (auto& x : to_merge) {
        merge(u, x);
    }
}

void add_edge(int u, int v) {
    v = root(v);
    if (v == root(u)) {
        return;
    }
    if (!in_v[v].count(u)) {
        ans += (long long) members[v].size();
        in_v[v].insert(u);
    }
    u = root(u);
    in_group[v].insert(u);
    out_group[u].insert(v);
    if (in_group[u].count(v)) {
        merge(u, v);
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> n >> m;
    p.resize(n + 1);
    iota(p.begin(), p.end(), 0);
    in_v.resize(n + 1);
    in_group.resize(n + 1);
    out_group.resize(n + 1);
    members.resize(n + 1);
    for (int i = 1; i <= n; i++) {
        members[i].insert(i);
    }
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        add_edge(u, v);
        cout << ans << '\n';
    }
    return 0;
}

• Subtask 1: 1 / 1
• Subtask 2: 16 / 16
• Subtask 3: 83 / 83