Submission #1168799

#	Time	Username	Problem	Language	Result	Execution time	Memory
1168799		steveonalex	Village (BOI20_village)	C++20	100 / 100	54 ms	22068 KiB

Village

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

#define MASK(i) (1ULL << (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(ull 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());
    }

const int N = 1e5 + 69, INF = 1e9 + 69;
int n;
vector<int> graph[N];
int sz[N];
ll ans1 = 0, ans2 = 0;

pair<int, int> dp[N];
vector<int> st;
vector<vector<int>> lemeat;


void dfs(int u, int p){
    sz[u] = 1;
    dp[u] = {1, 0};
    st.push_back(u);
    for(int v: graph[u]) if (v != p){
        dfs(v, u);
        sz[u] += sz[v];
        ans2 += min(sz[v], n - sz[v]);

        if (dp[v].first >= 2){
            dp[u].second += dp[v].second;

            lemeat.emplace_back();
            while(st.back() != v){
                lemeat.back().push_back(st.back());
                st.pop_back();
            }
            st.pop_back();
            lemeat.back().push_back(v);
        }
        else{
            dp[u].first += dp[v].first;
            dp[u].second += dp[v].second + 1;
        }
    }
}

namespace Sub1{
    vector<int> solve(){
        vector<int> ans(n+1);
        for(vector<int> a: lemeat){
            for(int i = 0; i < (int) a.size(); ++i){
                int j = (i + 1) % a.size();
                ans[a[j]] = a[i];
            }
        }

        return ans;
    }
}

namespace Sub2{

    int find_centroid(int u){
        for(int v: graph[u]){
            if (sz[v] * 2 <= sz[u]) continue;
            sz[u] -= sz[v];
            sz[v] += sz[u];
            return find_centroid(v);
        }
        return u;
    }

    void get_ver_set(int u, int p, vector<int> &ver){
        ver.push_back(u);
        for(int v: graph[u]) if (v != p){
            get_ver_set(v, u, ver);
        }
    }
    vector<int> solve(){
        vector<int> order;

        int root = find_centroid(1);

        vector<vector<int>> sigma;
        sigma.push_back({root});
        for(int i: graph[root]){
            vector<int> ver;
            get_ver_set(i, root, ver);
            sigma.push_back(ver);
        }

        priority_queue<pair<int,int>> pq;
        for(int i = 0; i < (int) sigma.size(); ++i) pq.push(make_pair(sigma[i].size(), i));

        while(pq.size()){
            pair<int, int> u = pq.top(); pq.pop();
            order.push_back(sigma[u.second].back());
//            ans.push_back(u.second);
            sigma[u.second].pop_back();

            if (pq.empty()) break;

            pair<int, int> v = pq.top(); pq.pop();
            order.push_back(sigma[v.second].back());
//            ans.push_back(v.second);
            sigma[v.second].pop_back();

            u.first--; v.first--;
            if (u.first > 0) pq.push(u);
            if (v.first > 0) pq.push(v);
        }

        vector<int> ans(n+1);

        for(int i = 0; i < (int) order.size(); ++i){
            int j = (i+1) % order.size();
            ans[order[j]] = order[i];
        }

        return ans;
    }
}
void solve(){
    cin >> n;
    for(int i = 1; i < n; ++i){
        int u, v; cin >> u >> v;
        graph[u].push_back(v);
        graph[v].push_back(u);
    }

    dfs(1, 0);

    ans1 = dp[1].second + (dp[1].first == 1);
    if (dp[1].first == 1){
        lemeat.back().push_back(1);
    }
    else{
        lemeat.push_back(st);
    }

    ans1 *= 2;
    ans2 *= 2;
    cout << ans1 << " " << ans2 << "\n";

    vector<int> min_ass = Sub1::solve();
    vector<int> max_ass = Sub2::solve();

    for(int i = 1; i <= n; ++i) cout << min_ass[i] << " "; cout << "\n";
    for(int i = 1; i <= n; ++i) cout << max_ass[i] << " "; cout << "\n";
}

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

    solve();

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

• Subtask 1: 12 / 12
• Subtask 2: 38 / 38
• Subtask 3: 50 / 50