Submission #431081

#	Time	Username	Problem	Language	Result	Execution time	Memory
431081		2qbingxuan	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	17 / 100	961 ms	30540 KiB

joitter2

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
#ifdef local
#define safe cerr<<__PRETTY_FUNCTION__<<" line "<<__LINE__<<" safe\n"
#define pary(a...) danb(#a, a)
#define debug(a...) qqbx(#a, a)
template <typename ...T> void qqbx(const char *s, T ...a) {
    int cnt = sizeof...(T);
    ((std::cerr << "\033[1;32m(" << s << ") = (") , ... , (std::cerr << a << (--cnt ? ", " : ")\033[0m\n")));
}
template <typename T> void danb(const char *s, T L, T R) {
    std::cerr << "\033[1;32m[ " << s << " ] = [ ";
    for (int f = 0; L != R; ++L)
        std::cerr << (f++ ? ", " : "") << *L;
    std::cerr << " ]\033[0m\n";
}
#else
#define debug(...) ((void)0)
#define safe ((void)0)
#define pary(...) ((void)0)
#endif // local
#define all(v) begin(v),end(v)
#define pb emplace_back
#define sort_uni(v) sort(all(v)),v.erase(unique(all(v)),v.end())

using namespace std;
using ll = long long;
using ld = long double;
template <typename T> using min_heap = priority_queue<T, vector<T>, greater<T>>;
const int mod = 1000000007;
const int inf = 1e9;
const ll INF = 1e18;
const int maxn = 100025;

int pa[maxn], sz[maxn];
int anc(int x) { return x==pa[x] ? x : pa[x]=anc(pa[x]); }
set<int> in[maxn], cc[maxn];
ll ans = 0;
bool join(int x, int y) {
    x = anc(x);
    y = anc(y);
    if (x == y)
        return false;
    if (sz[x] > sz[y]) swap(x, y);
    ans -= 1LL * sz[x] * (sz[x] - 1) + sz[x] * ll(in[x].size());
    ans -= 1LL * sz[y] * (sz[y] - 1) + sz[y] * ll(in[y].size());
    pa[x] = y;
    sz[y] += sz[x];
    for (int i: cc[x]) in[y].erase(i);
    for (int i: cc[x]) cc[y].insert(i);
    for (int i: in[x]) if (!cc[y].count(i)) in[y].insert(i);
    ans += 1LL * sz[y] * (sz[y] - 1) + sz[y] * ll(in[y].size());
    return true;
}
int ADJ[2025][2025];
signed main() {
    ios_base::sync_with_stdio(0), cin.tie(0);
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < n; i++) pa[i] = i, sz[i] = 1, cc[i].insert(i);
    vector<pair<int,int>> edges;
    while (m--) {
        int a, b;
        cin >> a >> b;
        --a, --b;
        if (ADJ[anc(b)][anc(a)]) {
            int x = a, y = b;
            while (x != -1 && y != -1 && join(x, y)) {
                for (auto [s, t]: edges) ADJ[s][t] = 0;
                vector<pair<int,int>> tmp;
                tmp.reserve(edges.size());
                pair<int,int> jizz(-1, -1);
                for (auto [s, t]: edges) {
                    s = anc(s);
                    t = anc(t);
                    if (s != t) {
                        if (ADJ[t][s])
                            jizz = { s, t };
                        ADJ[s][t] = 1;
                        tmp.emplace_back(s, t);
                    }
                }
                edges = tmp;
                tie(x, y) = jizz;
            }
        } else {
            edges.emplace_back(anc(a), anc(b));
            ADJ[anc(a)][anc(b)] = 1;
        }
        /*
        if (edges.count({ anc(b), anc(a) })) {
            int x = a, y = b;
            while (x != -1 && y != -1) {
                join(x, y);
                set<pair<int,int>> tmp;
                pair<int,int> jizz(-1, -1);
                for (auto [s, t]: edges) {
                    s = anc(s);
                    t = anc(t);
                    if (s != t) {
                        if (tmp.count({ t, s }))
                            jizz = { s, t };
                        tmp.insert({ s, t });
                    }
                }
                edges = tmp;
                tie(x, y) = jizz;
            }
        }
        edges.insert({ anc(a), anc(b) });
        */
        if (anc(a) != anc(b)) {
            if (!in[anc(b)].count(a))
                ans += sz[anc(b)];
            in[anc(b)].insert(a);
        }
        cout << ans << '\n';
    }
}

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