제출 #1168510

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1168510		1bin	Making Friends on Joitter is Fun (JOI20_joitter2)	C++20	0 / 100	9 ms	14412 KiB

joitter2

#include <bits/stdc++.h>

using namespace std;

#define all(v) v.begin(), v.end()
typedef long long ll;
const int NMAX = 1e5 + 5;
ll n, m, par[NMAX], sz[NMAX], ans, a, b, pa, pb;
set<int> v[NMAX], in[NMAX], out[NMAX];
int find(int x){return par[x] == -1 ? x : par[x] = find(par[x]);}
queue<pair<int, int>> q;

void add(int a, int f) {
    ll c = v[a].size() - sz[a];
    if (f == -1) ans -= sz[a] * (sz[a] - 1) + sz[a] * c;
    else ans += sz[a] * (sz[a] - 1) + sz[a] * c;
}

void merge(int a, int b) {
    add(a, -1); add(b, -1);
    if (v[a].size() + out[a].size() + in[a].size() < v[b].size() + out[b].size() + in[b].size()) swap(a, b);
    par[b] = a; sz[a] += sz[b];
    in[a].erase(b); out[a].erase(b);
    in[b].erase(a); out[b].erase(a);

    for (auto& t : v[b]) v[a].emplace(t);
    for (auto&t : out[b]) {
        in[t].erase(b);
        q.emplace(a, t);
    }
    for (auto&t : in[b]) {
        out[t].erase(b);
        q.emplace(t, a);
    }
    add(a, 1);
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    cin >> n >> m;
    for (int i = 1; i <= n; i++) {
        v[i].emplace(i);
        sz[i] = 1; par[i] = -1;
    }

    while (m--) {
        cin >> a >> b;
        q.emplace(a, b);
        while (q.size()) {
            auto[a, b] = q.front(); q.pop();
            pa = find(a); pb = find(b);
            if (pa == pb) continue;

            add(pb, -1);
            v[pb].emplace(a);
            out[pa].emplace(pb); in[pb].emplace(pa);
            add(pb, 1);
            if (out[pb].find(pa) != out[pb].end()) merge(pa, pb);
        }
        cout << ans << '\n';
    }
    return 0;
}

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