제출 #583082

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
583082		elkernos	조이터에서 친구를 만드는건 재밌어 (JOI20_joitter2)	C++17	0 / 100	1 ms	340 KiB

joitter2

#include <bits/stdc++.h>

using namespace std;

int main()
{
    cin.tie(nullptr)->sync_with_stdio(0);
    int n;
    cin >> n;
    vector<set<int>> g(n + 1);
    vector<set<pair<int, int>>> rg(n + 1);
    vector<int> r(n + 1), sz(n + 1);
    function<int(int)> f = [&](int x) {
        return x == r[x] ? x : r[x] = f(r[x]);
    };
    long long ans = 0;
    function<void(int, int)> u = [&](int a, int b) {
        if(sz[a] < sz[b]) { // b do a
            swap(a, b);
        }
        auto remove_all = [&](int aa, int bb) {
            set<pair<int, int>>::iterator it;
            while((it = rg[bb].lower_bound({aa, 0})) != rg[bb].end() && it->first == aa) {
                ans -= sz[bb];
                rg[bb].erase(it);
            }
        };
        remove_all(a, b);
        g[a].erase(b);
        remove_all(b, a);
        g[b].erase(a);
        vector<int> todo;
        for(int x : g[b]) {
            set<pair<int, int>>::iterator it;
            while((it = rg[x].lower_bound({b, 0})) != rg[x].end() && it->first == b) {
                int t = it->second;
                rg[x].erase(it);
                rg[x].insert({a, t});
            }
            g[a].insert(x);
            if(g[x].count(a)) {
                todo.push_back(x);
            }
        }
        ans += (long long)sz[b] * rg[a].size();
        for(pair<int, int> x : rg[b]) {
            g[x.first].erase(b);
            g[x.first].insert(a);
            if(!rg[a].count(x)) {
                ans += sz[a];
                rg[a].insert(x);
            }
            else {
                ans -= sz[b]; // overcounted in line 51
            }
            if(g[a].count(x.first)) {
                todo.push_back(x.first);
            }
        }
        ans -= (long long)sz[a] * (sz[a] - 1);
        ans -= (long long)sz[b] * (sz[b] - 1);
        r[b] = a;
        sz[a] += sz[b];
        ans += (long long)sz[a] * (sz[a] - 1);
        for(int x : todo) {
            u(a, x);
        }
    };
    auto edge = [&](int a, int b) { // a -> b
        int v = a;
        a = f(a);
        b = f(b);
        if(a == b) {
            return;
        }
        if(!rg[b].count({a, v})) {
            ans += sz[b];
            rg[b].insert({a, v});
            g[a].insert(b);
        }
        if(g[a].count(b) && g[b].count(a)) {
            u(a, b);
        }
    };
    for(int i = 1; i <= n; i++) {
        r[i] = i;
        sz[i] = 1;
    }
    int m;
    cin >> m;
    for(int i = 1; i <= m; i++) {
        int a, b;
        cin >> a >> b;
        edge(a, b);
        cout << ans << '\n';
    }
}

• Subtask 1: 0 / 1
• Subtask 2: 0 / 16
• Subtask 3: 0 / 83