Submission #431110

#	Time	Username	Problem	Language	Result	Execution time	Memory
431110		2qbingxuan	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	100 / 100	1753 ms	98416 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];
set<int> s_in[maxn], s_out[maxn];
queue<pair<int,int>> que;
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 z: s_in[x]) {
        if (s_out[y].count(z)) {
            que.emplace(y, z);
        }
    }
    for (int z: s_out[x]) {
        if (s_in[y].count(z)) {
            que.emplace(y, z);
        }
    }
    for (int z: s_out[x]) {
        s_in[z].erase(x);
        s_in[z].insert(y);
    }
    for (int z: s_in[x]) {
        s_out[z].erase(x);
        s_out[z].insert(y);
    }
    s_in[y].erase(x);
    s_out[y].erase(x);
    for (int z: s_out[x])
        if (z != y)
            s_out[y].insert(z);
    for (int z: s_in[x])
        if (z != y)
            s_in[y].insert(z);

    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 (s_out[anc(b)].count(anc(a))) {
            que.emplace(a, b);
            while (!que.empty()) {
                auto [s, t] = que.front(); que.pop();
                join(s, t);
            }
        }
        if (anc(a) != anc(b)) {
            s_out[anc(a)].insert(anc(b));
            s_in[anc(b)].insert(anc(a));

            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: 83 / 83