Submission #1091078

#	Time	Username	Problem	Language	Result	Execution time	Memory
1091078		steveonalex	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	0 / 100	1 ms	456 KiB

joitter2

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
#define block_of_code if(true)
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

pair<int, int> make_edge(int u, int v){
    if (u <= v) return make_pair(u, v);
    return make_pair(v, u);
}

struct DSU{
    int n;
    vector<int> parent, sz;
    vector<vector<int>> ver;
    vector<set<int>> S1, S2, drake;
    set<pair<int, int>> pending_merge;
    ll ans;

    DSU(int _n){
        n = _n;
        parent.resize(n+1); sz.resize(n+1, 1);
        S1.resize(n+1); S2.resize(n+1); drake.resize(n+1);
        ver.resize(n+1);
        for(int i = 1; i<=n; ++i) {
            parent[i] = i;
            ver[i].push_back(i);
        }
        ans = 0;
    }

    int find_set(int u){return (u == parent[u]) ? u : (parent[u] = find_set(parent[u]));}
    bool same_set(int u, int v){return find_set(u) == find_set(v);}

    bool join_set(int u, int v){
        u = find_set(u), v = find_set(v);
        ans += 2LL * sz[u] * sz[v];
        S1[u].erase(v); S2[u].erase(v); 
        S1[v].erase(u); S2[v].erase(u);
        ans -= 1LL * sz[v] * drake[v].size() + 1LL * sz[u] * drake[u].size();
        if (u != v){
            if (sz[u] < sz[v]) swap(u, v);
            parent[v] = u;
            sz[u] += sz[v];
            vector<pair<int, int>> pending;
            for(int i: S1[v]) {
                S2[i].erase(v); S2[i].insert(u);
                S1[u].insert(i);
                if (S2[u].find(i) != S2[u].end()) pending_merge.insert({u, i});
            }
            for(int i: S2[v]){
                S1[i].erase(v); S1[i].insert(u);
                S2[u].insert(i);
                if (S1[u].find(i) != S1[u].end()) pending_merge.insert({u, i}); 
            }
            for(int i: ver[v]) drake[u].erase(i);
            ans += 1LL * sz[u] * drake[u].size();
            for(int i: drake[v]) if (!same_set(u, i)) add_drake(u, i);

            for(int i: ver[v]) ver[u].push_back(i);
            return true;
        }
        return false;
    }

    void add_drake(int u, int v){
        if (drake[u].insert(v).second) {
            ans += get_size(u);
        }
    }

    int get_size(int u){return sz[find_set(u)];}
    ll get_ans(){return ans;}

    void add_edge(int u, int v){
        int _u = u;
        u = find_set(u), v = find_set(v);
        S1[u].insert(v); S2[v].insert(u);
        add_drake(v, _u);
        if (S2[u].find(v) != S2[u].end()) pending_merge.insert({u, v});

        while(pending_merge.size()){
            int x, y; tie(x, y) = *pending_merge.begin();
            pending_merge.erase(pending_merge.begin());
            join_set(x, y);
        }
    }
};

int main(void){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
    clock_t start = clock();

    int n, m; cin >> n >> m;

    DSU mst(n);
    for(int i = 0; i<m; ++i){
        int u, v; cin >> u >> v;

        if (!mst.same_set(u, v)) mst.add_edge(u, v);
        ll ans = mst.get_ans();

        cout << ans << "\n";
    }

    cerr << "Time elapsed: " << clock() - start << " ms\n";
    return 0;
}

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