Submission #963594

#	Time	Username	Problem	Language	Result	Execution time	Memory
963594		GrindMachine	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	0 / 100	1 ms	348 KiB

joitter2

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

read some solutions some time ago, remember some ideas from there

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

struct DSU {
    vector<int> par, rankk, siz;
    vector<set<int>> inc, out;

    DSU() {

    }

    DSU(int n) {
        init(n);
    }

    void init(int n) {
        par = vector<int>(n + 1);
        rankk = vector<int>(n + 1);
        siz = vector<int>(n + 1);
        inc = vector<set<int>>(n + 1);
        out = vector<set<int>>(n + 1);
        rep(i, n + 1) create(i);
    }

    void create(int u) {
        par[u] = u;
        rankk[u] = 0;
        siz[u] = 1;
    }

    int find(int u) {
        if (u == par[u]) return u;
        else return par[u] = find(par[u]);
    }

    bool same(int u, int v) {
        return find(u) == find(v);
    }

    void merge(int u, int v) {
        u = find(u), v = find(v);
        if (u == v) return;

        if (rankk[u] == rankk[v]) rankk[u]++;
        if (rankk[u] < rankk[v]) swap(u, v);

        par[v] = u;
        siz[u] += siz[v];
    }

    void go(int u, int v){
        // merge u and v
        if(same(u,v)) return;
        merge(u,v);
        out[u].erase(v);
        inc[u].erase(v);
        out[v].erase(u);
        inc[v].erase(u);

        vector<pii> pending;

        trav(x,out[v]){
            out[u].insert(x);
            if(inc[u].count(x)){
                pending.pb({u,x});
            }
        }

        trav(x,inc[v]){
            inc[u].insert(x);
            if(out[u].count(x)){
                pending.pb({u,x});
            }
        }

        out[v].clear();
        inc[v].clear();

        for(auto [x,y] : pending){
            go(x,y);
        }
    }

    void add_edge(int u, int v){
        u = find(u), v = find(v);
        if(u == v or out[u].count(v)) return;

        out[u].insert(v);
        inc[v].insert(u);

        if(inc[u].count(v)){
            // merge
            go(u,v);
        }
    }
};

void solve(int test_case)
{
    ll n,m; cin >> n >> m;
    DSU dsu(n+5);

    rep1(i,m){
        ll u,v; cin >> u >> v;
        dsu.add_edge(u,v);
        ll ans = 0;
        rep1(i,n){
            if(dsu.find(i) != i) conts;
            ll s = dsu.siz[i];
            ans += s*(s-1);
        }
        rep1(i,n){
            ll s = dsu.siz[dsu.find(i)];
            trav(cc,dsu.inc[i]){
                ans += dsu.siz[cc]*s;
            }
        }

        cout << ans << endl;
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

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