Submission #430890

#	Time	Username	Problem	Language	Result	Execution time	Memory
430890		2qbingxuan	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	0 / 100	1 ms	204 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

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]); }
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;
    set<pair<int,int>> st;
    while (m--) {
        int a, b;
        cin >> a >> b;
        --a, --b;
        a = anc(a), b = anc(b);
        if (a != b) {
            debug(st.count({a, b}));
            if (st.count({ b, a })) {
                pa[a] = b;
                sz[b] += sz[a];
                set<pair<int,int>> tmp;
                for (auto [s, t]: st)
                    if (anc(s) != anc(t))
                        tmp.insert({ anc(s), anc(t) });
                st = tmp;
            } else {
                st.insert({ a, b });
            }
        }

        ll ans = 0;
        for (auto [s, t]: st)
            if (sz[t] != 1)
                ans += 1LL * sz[s] * sz[t];
            else
                ++ans;
        for (int i = 0; i < n; i++) if (anc(i) == i)
            ans += 1LL * sz[i] * (sz[i] - 1);
        cout << ans << '\n';
        // addEdge(anc(a), anc(b));
        // out[a].emplace_back(b);
        // in[b].emplace_back(a);
    }
}

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