結果

問題 No.3272 Separate Contractions
ユーザー umimel
提出日時 2025-09-13 03:10:06
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 423 ms / 3,000 ms
コード長 8,938 bytes
コンパイル時間 2,812 ms
コンパイル使用メモリ 189,780 KB
実行使用メモリ 60,240 KB
最終ジャッジ日時 2025-09-13 03:10:27
合計ジャッジ時間 17,016 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge5
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 43
権限があれば一括ダウンロードができます
コンパイルメッセージ
main.cpp: In function ‘void solve()’:
main.cpp:187:10: warning: structured bindings only available with ‘-std=c++17’ or ‘-std=gnu++17’ [-Wc++17-extensions]
  187 |     auto [s, t] = diam.get_endpoints();
      |          ^

ソースコード

diff # 

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second
mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
const ll MOD1000000007 = 1000000007;
const ll MOD998244353 = 998244353;
const ll MOD[3] = {999727999, 1070777777, 1000000007};
const ll LINF = 1LL << 60LL;
const int IINF = (1 << 30) - 1;


template<typename T> 
struct edge{
    int from;
    int to;
    T cost;
    int id;

    edge(){}
    edge(int to, T cost=1) : from(-1), to(to), cost(cost){}
    edge(int from, int to, T cost) : from(from), to(to), cost(cost) {}
    edge(int from, int to, T cost, int id) : from(from), to(to), cost(cost), id(id){}

    void reverse(){swap(from, to);}
};

template<typename T>
struct edges : std::vector<edge<T>>{
    void sort(){
        std::sort(
            (*this).begin(),
            (*this).end(), 
            [](const edge<T>& a, const edge<T>& b){
                return a.cost < b.cost;
            }
        );
    }
};

template<typename T = bool>
struct graph : std::vector<edges<T>>{
private:
    int n = 0;
    int m = 0;
    edges<T> es;
    bool dir;

public:
    graph(int n, bool dir) : n(n), dir(dir){
        (*this).resize(n);
    }

    void add_edge(int from, int to, T cost=1){
        if(dir){
            es.push_back(edge<T>(from, to, cost, m));
            (*this)[from].push_back(edge<T>(from, to, cost, m++));
        }else{
            if(from > to) swap(from, to);
            es.push_back(edge<T>(from, to, cost, m));
            (*this)[from].push_back(edge<T>(from, to, cost, m));
            (*this)[to].push_back(edge<T>(to, from, cost, m++));
        }
    }

    int get_vnum(){
        return n;
    }

    int get_enum(){
        return m;
    }

    bool get_dir(){
        return dir;
    }

    edge<T> get_edge(int i){
        return es[i];
    }

    edges<T> get_edge_set(){
        return es;
    }
};

template<typename T>
struct redge{
    int from, to;
    T cap, cost;
    int rev;
    
    redge(int to, T cap, T cost=(T)(1)) : from(-1), to(to), cap(cap), cost(cost){}
    redge(int to, T cap, T cost, int rev) : from(-1), to(to), cap(cap), cost(cost), rev(rev){}
};

template<typename T> using Edges = vector<edge<T>>;
template<typename T> using weighted_graph = vector<Edges<T>>;
template<typename T> using tree = vector<Edges<T>>;
using unweighted_graph = vector<vector<int>>;
template<typename T> using residual_graph = vector<vector<redge<T>>>;


template<typename S>
struct diameter{
    int n;
    int s=0, t=0;
    vector<int> path;
    S diam = 0;

    diameter(graph<S> &T){
        n = (int)T.size();

        vector<S> dist1(n, 0);
        function<void(int, int)> dfs1 = [&](int v, int p){
            for(auto e : T[v]) if(e.to!=p){
                dist1[e.to] = dist1[v] + e.cost;
                dfs1(e.to, v);
            }
        };
        dfs1(0, -1);
        S sdist = 0;
        for(int v=0; v<n; v++){
            if(sdist < dist1[v]){
                s = v;
                sdist = dist1[v];
            }
        }

        vector<S> dist2(n, 0);
        function<void(int, int)> dfs2 = [&](int v, int p){
            for(auto e : T[v]) if(e.to!=p){
                dist2[e.to] = dist2[v] + e.cost;
                dfs2(e.to, v);
            }
        };
        dfs2(s, -1);
        S tdist = 0;
        for(int v=0; v<n; v++){
            if(tdist < dist2[v]){
                t = v;
                tdist = dist2[v];
            }
        }

        diam = tdist;

        function<bool(int, int)> dfs3 = [&](int v, int p){
            if(v == t){
                path.pb(v);
                return true;
            }

            bool flag = false;
            for(auto e : T[v]) if(e.to!=p){
                flag = flag | dfs3(e.to, v);
            }

            if(flag) path.pb(v);
            return flag;
        };

        dfs3(s, -1);
        reverse(path.begin(), path.end());
    }

    pair<int, int> get_endpoints(){return {s, t};}
    vector<int> get_path(){return path;}
    S get_distance(){return diam;}
};

void solve(){
    int n; cin >> n;
    graph<int> T(n, false);
    for(int i=0; i<n-1; i++){
        int u, v; cin >> u >> v;
        u--; v--;
        T.add_edge(u, v);
    }

    diameter<int> diam(T);
    auto [s, t] = diam.get_endpoints();
    auto P = diam.get_path();
    int D = diam.get_distance();

    vector<int> ePath;
    for(int i=0; i<D; i++){
        int v = P[i], w = P[i+1];
        for(auto e : T[v]) if(e.to==w) ePath.pb(e.id);
    }
    
    function<void(int, int, vector<int>&)> calc_dist = [&](int v, int p, vector<int> &dist){
        for(auto e : T[v]) if(e.to!=p){
            dist[e.to] = dist[v] + 1;
            calc_dist(e.to, v, dist);
        }
    };

    vector<int> sdist(n, 0), tdist(n, 0);
    calc_dist(s, -1, sdist);
    calc_dist(t, -1, tdist);

    vector<bool> onP(n, false); for(int v : P) onP[v] = true;

    vector<ll> ans(n-1, 0);
    ll U = 0;
    for(int i=0; i<n; i++) U += max(sdist[i], tdist[i]);

    vector<vector<int>> anc(n);

    // Case1 : P上にない辺の答えを計算
    {
        vector<int> siz(n, 1);
        function<void(int, int, int)> dfs = [&](int v, int p, int r){
            anc[r].pb(v);
            for(auto e : T[v]) if(e.to!=p && !onP[e.to]){
                dfs(e.to, v, r);
                ans[e.id] = U - (siz[e.to]-1) - max(sdist[e.to], tdist[e.to]);
                siz[v] += siz[e.to];
            }
        }; 
        for(int v : P) dfs(v, -1, v);
    }

    // Case2 : D is even
    if(D%2 == 0){
        //　Case2-1 : e_0, e_1, ..., e_(D/2-1)を縮約
        {
            vector<int> d(D+1, 0);
            for(int i=D-1; i>=0; i--){
                d[i] = d[i+1];
                for(int v : anc[P[i]]) d[i] = max(d[i], tdist[v]);
            }

            // 前から探索
            int lsum = 0;
            int rsum = 0; for(int i=D; i>D/2; i--) rsum += anc[P[i]].size();
            for(int i=0; i<D/2; i++){ // 辺ePath[i]を縮約
                lsum += anc[P[i]].size();
                if(d[i+1] == D){
                    ans[ePath[i]] = U - (lsum-1) - tdist[P[i]];
                }else{
                    ans[ePath[i]] = U - (lsum-1) - tdist[P[i]] - rsum;
                }
            }
        }

        // Case2-2 : e_(D/2), e_(D/2+1), ..., e_(D-1)を縮約
        {
            vector<int> d(D+1, 0);
            for(int i=1; i<=D; i++){
                d[i] = d[i-1];
                for(int v : anc[P[i]]) d[i] = max(d[i], sdist[v]);
            }

            // 後ろから探索
            int lsum = 0; for(int i=0; i<D/2; i++) lsum += anc[P[i]].size();
            int rsum = 0;
            for(int i=D-1; i>=D/2; i--){ // 辺ePath[i]を縮約
                rsum += anc[P[i+1]].size();
                if(d[i] == D){
                    ans[ePath[i]] = U - (rsum-1) - sdist[P[i+1]];
                }else{
                    ans[ePath[i]] = U - (rsum-1) - sdist[P[i+1]] - lsum;
                }
            }
        }
    }

    // Case3 : D is odd
    if(D%2 == 1){
        // Case3-1 : e_0, e_1, ..., e_(D/2-1)を縮約
        {
            vector<int> d(D+1, 0);
            for(int i=D-1; i>=0; i--){
                d[i] = d[i+1];
                for(int v : anc[P[i]]) d[i] = max(d[i], tdist[v]);
            }

            // 前から探索
            int lsum = 0;
            int rsum = 0; for(int i=D; i>D/2; i--) rsum += anc[P[i]].size();
            for(int i=0; i<D/2; i++){ // 辺ePath[i]を縮約
                lsum += anc[P[i]].size();
                if(d[i+1] == D){
                    ans[ePath[i]] = U - (lsum-1) - tdist[P[i]];
                }else{
                    ans[ePath[i]] = U - (lsum-1) - tdist[P[i]] - rsum;
                }
            }
        }

        // Case3-2 : e_(D/2) を縮約
        ans[ePath[D/2]] = U-(n-1)-max(sdist[P[D/2]], tdist[P[D/2]]);
        
        // Case3-3 : e_(D/2+1), e_(D/2+2), ..., e_(D-1)を縮約
        {
            vector<int> d(D+1, 0);
            for(int i=1; i<=D; i++){
                d[i] = d[i-1];
                for(int v : anc[P[i]]) d[i] = max(d[i], sdist[v]);
            }

            // 後ろから探索
            int lsum = 0; for(int i=0; i<=D/2; i++) lsum += anc[P[i]].size();
            int rsum = 0;
            for(int i=D-1; i>=D/2+1; i--){ // 辺ePath[i]を縮約
                rsum += anc[P[i+1]].size();
                if(d[i] == D){
                    ans[ePath[i]] = U - (rsum-1) - sdist[P[i+1]];
                }else{
                    ans[ePath[i]] = U - (rsum-1) - sdist[P[i+1]] - lsum;
                }
            }
        }
    }

    for(int i=0; i<n-1; i++) cout << ans[i] << "\n";
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    
    int T=1;
    //cin >> T;
    while(T--) solve();
}
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