Submission #873931

#	Time	Username	Problem	Language	Result	Execution time	Memory
873931		noiaint	Marshmallow Molecules (CCO19_day2problem2)	C++17	25 / 25	129 ms	53688 KiB

Main

#include <bits/stdc++.h>

using namespace std;

#define file ""

#define mp make_pair
#define fi first
#define se second
#define all(x) x.begin(), x.end()

#define getbit(x, i) (((x) >> (i)) & 1)
#define bit(x) (1LL << (x))
#define popcount __builtin_popcountll

mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) {
    return l + rd() % (r - l + 1);
}

const int N = 1e6 + 5;
const int mod = (int)1e9 + 7; // 998244353;
const int lg = 25; // lg + 1
const int oo = 1e9;
const long long ooo = 1e18;

template<class X, class Y> bool mini(X &a, Y b) {
    return a > b ? (a = b, true) : false;
}
template<class X, class Y> bool maxi(X &a, Y b) {
    return a < b ? (a = b, true) : false;
}
void add(int &a, int b) {
    a += b;
    if (a >= mod) a -= mod;
    if (a < 0) a += mod;
}

int n, m;
set<int> adj[N];

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    // freopen(file".inp", "r", stdin);
    // freopen(file".out", "w", stdout);

    cin >> n >> m;
    for (int i = 1; i <= m; ++i) {
        int u, v;
        cin >> u >> v;
        if (u > v) swap(u, v);
        adj[u].insert(v);
    }

    long long ans = 0;

    for (int u = 1; u <= n; ++u) if (adj[u].size()) {        
        ans += adj[u].size();

        int v = *adj[u].begin();
        adj[u].erase(adj[u].begin());
        if (adj[u].size() > adj[v].size()) swap(adj[u], adj[v]);
        for (int x : adj[u]) adj[v].insert(x);

        adj[u].clear();

        /*
        int node a, find b such that a > b -> adj[a].begin()
        merge a and b
        */
    }

    cout << ans << '\n';

    return 0;
}

/*

*/

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 10 / 10