Submission #1171013

#	Time	Username	Problem	Language	Result	Execution time	Memory
1171013		SmuggingSpun	Making Friends on Joitter is Fun (JOI20_joitter2)	C++20	100 / 100	1435 ms	73680 KiB

joitter2

#include<bits/stdc++.h>
#define taskname "B"
using namespace std;
typedef long long ll;
int n, m;
namespace sub1{
    void solve(){
        vector<ll>g(n, 0), _g;
        for(int _ = 0; _ < m; _++){
            int u, v;
            cin >> u >> v;
            g[--u] |= 1LL << --v;
            _g = g;
            while(true){
                bool flag = false;
                for(int i = 0; i < n; i++){
                    for(int j = 0; j < n; j++){
                        if(1LL << j & _g[i]){
                            for(int k = 0; k < n; k++){
                                if(k != i && k != j && (1LL << j & _g[k]) && (1LL << k & _g[j]) && ((_g[i] >> ll(k) & 1LL) == 0)){
                                    _g[i] |= 1LL << k;
                                    flag = true;
                                }
                            }
                        }
                    }
                }
                if(!flag){
                    break;
                }
            }
            int ans = 0;
            for(int i = 0; i < n; i++){
                ans += __builtin_popcountll(_g[i]);
            }
            cout << ans << "\n";
        }
    }
}
namespace sub23{
    const int lim = 2e5 + 5;
    int size[lim], parent[lim];
    ll ans = 0;
    set<pair<int, int>>out[lim];
    set<int>in[lim], in_set[lim];
    queue<pair<int, int>>q;
    int find_set(int N){
        while(N != parent[N]){
            N = parent[N] = parent[parent[N]];
        }
        return N;
    }
    bool add_edge(int u, int v){
        if(find_set(u) == find_set(v) || out[find_set(u)].find(make_pair(u, find_set(v))) != out[find_set(u)].end()){
            return false;
        }
        in[find_set(v)].insert(u);
        out[find_set(u)].emplace(u, find_set(v));
        in_set[find_set(v)].insert(find_set(u));
        if(in_set[find_set(u)].find(find_set(v)) != in_set[find_set(u)].end()){
            q.emplace(u, v);
        }
        return true;
    }
    ll cal(int u){
        return 1LL * size[u = find_set(u)] * (size[u] - 1 + in[u].size());
    }
    void merge(){
        auto [u, v] = q.front();
        q.pop();
        if((u = find_set(u)) == (v = find_set(v))){
            return;
        }
        if(in[u].size() + out[u].size() < in[v].size() + out[v].size()){
            swap(u, v);
        }
        ans -= cal(u);
        ans -= cal(v);
        vector<pair<int, int>>add, remove;
        for(const int& x : in[v]){
            remove.emplace_back(x, v);
            if(find_set(x) != v){
                add.emplace_back(x ,v);
            }
        }
        for(auto& [a, b] : out[v]){
            remove.emplace_back(a, b);
            if(b != u){
                add.emplace_back(a, b);
            }
        }
        for(auto& [a, b] : remove){
            out[find_set(a)].erase(make_pair(a, find_set(b)));
            in[find_set(b)].erase(a);
        }
        size[parent[v] = u] += size[v];
        for(auto& [a, b] : add){
            add_edge(a, b);
        }
        ans += cal(u);
    }
    void solve(){
        for(int i = 1; i <= n; i++){
            size[parent[i] = i] = 1;
        }
        for(int _ = 0; _ < m; _++){
            int u, v;
            cin >> u >> v;
            if(add_edge(u, v)){
                ans += size[find_set(v)];
            }
            while(!q.empty()){
                merge();
            }
            cout << ans << "\n";
        }
    }
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
    cin >> n >> m;
    if(n <= 50){
        sub1::solve();
    }
    else{
        sub23::solve();
    }
}

Compilation message (stderr)

joitter2.cpp: In function 'int main()':
joitter2.cpp:122:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  122 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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