結果

問題 No.872 All Tree Path
コンテスト
ユーザー ningenMe
提出日時 2019-08-29 22:50:42
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 409 ms / 3,000 ms
コード長 7,705 bytes
コンパイル時間 2,182 ms
コンパイル使用メモリ 184,204 KB
実行使用メモリ 43,236 KB
最終ジャッジ日時 2024-11-17 17:27:18
合計ジャッジ時間 7,182 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge4
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 * 2
other AC * 18
権限があれば一括ダウンロードができます

ソースコード

diff # 

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;

#define REP(i,n) for(long long i = 0; i < (n); i++)
#define FOR(i, m, n) for(long long i = (m);i < (n); ++i)
#define ALL(obj) (obj).begin(),(obj).end()
#define SPEED cin.tie(0);ios::sync_with_stdio(false);

template<class T> using V = vector<T>;
template<class T, class U> using P = pair<T, U>;
template<class T> using PQ = priority_queue<T>;
template<class T> using PQR = priority_queue<T,vector<T>,greater<T>>;

constexpr long long MOD = (long long)1e9 + 7;
constexpr long long MOD2 = 998244353;
constexpr long long HIGHINF = (long long)1e18;
constexpr long long LOWINF = (long long)1e15;
constexpr long double PI = 3.1415926535897932384626433;

template <class T> vector<T> make_v(size_t N,T init){return vector<T>(N,init);}
template <class... T> auto make_v(size_t N,T... t){return vector<decltype(make_v(t...))>(N,make_v(t...));}
template <class T> void corner(bool flg, T hoge) {if (flg) {cout << hoge << endl; exit(0);}}
template <class T, class U>ostream &operator<<(ostream &o, const map<T, U>&obj) {o << "{"; for (auto &x : obj) o << " {" << x.first << " : " << x.second << "}" << ","; o << " }"; return o;}
template <class T>ostream &operator<<(ostream &o, const set<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const multiset<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const vector<T>&obj) {o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o;}
template <class T, class U>ostream &operator<<(ostream &o, const pair<T, U>&obj) {o << "{" << obj.first << ", " << obj.second << "}"; return o;}
template <template <class tmp>  class T, class U> ostream &operator<<(ostream &o, const T<U> &obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr)o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
void print(void) {cout << endl;}
template <class Head> void print(Head&& head) {cout << head;print();}
template <class Head, class... Tail> void print(Head&& head, Tail&&... tail) {cout << head << " ";print(forward<Tail>(tail)...);}
template <class T> void chmax(T& a, const T b){a=max(a,b);}
template <class T> void chmin(T& a, const T b){a=min(a,b);}
void YN(bool flg) {cout << (flg ? "YES" : "NO") << endl;}
void Yn(bool flg) {cout << (flg ? "Yes" : "No") << endl;}
void yn(bool flg) {cout << (flg ? "yes" : "no") << endl;}

template<class T = int> class Tree {
public:
	int N;
	int is_weighted;
	int MAX_bit;
	int idx;
	vector<vector<int>> edge;
	vector<vector<T>> weight;
	vector<int> depth;
	vector<int> order;
	vector<T> dist;
	
	vector<int> parent;
	vector<T> parent_dist;
	
	vector<vector<int>> child;
	vector<vector<T>> child_dist;
 
	vector<vector<int>> ancestor;
	vector<vector<int>> descendant;
	
	vector<int> euler_tour;
    vector<T> euler_tour_dist;
	vector<int> idxl;
	vector<int> idxr;
 
	Tree(const int N, const int is_weighted = 0, const int MAX_bit = 20) : 
	N(N),
	is_weighted(is_weighted),
	MAX_bit(MAX_bit),
	edge(N),
	depth(N),
	order(N)
	{
		if(is_weighted) weight.resize(N);
		if(is_weighted) dist.resize(N);
	}
 
	//O(1) anytime
	void make_edge(const int& from, const int& to, const T& w = 0) {
		edge[from].push_back(to);
		if(is_weighted)	weight[from].push_back(w);
	}
 
	//O(N) anytime
	void make_depth(const int root) {
		depth[root] = 0;
		if(is_weighted) dist[root] = 0;
		idx = 0;
		dfs1(root);
		order[idx++] = root;
	}
 
    //for make_depth
	void dfs1(int from, int prev = -1){
		for(int i = 0; i < edge[from].size(); ++i){
			int to = edge[from][i];
			if(to==prev) continue;
			depth[to] = depth[from] + 1;
			if(is_weighted) dist[to] = dist[from] + weight[from][i];
			dfs1(to,from);
			order[idx++] = to;
		}
	}
 
    //O(N) anytime
	int diameter(void){
		make_depth(0);
		int tmp = max_element(depth.begin(), depth.end()) - depth.begin();
		make_depth(tmp);
		return *max_element(depth.begin(), depth.end());
	}
 
	//O(N) after make_depth
	void make_parent(void) {
		parent.resize(N);
		iota(parent.begin(),parent.end(),0);
		for (int i = 0; i < N; ++i) for (auto j : edge[i]) if (depth[i] > depth[j]) parent[i] = j;
 
		if(is_weighted) {
			parent_dist.resize(N);
			for (int i = 0; i < N; ++i) for (int j = 0; j < edge[i].size(); ++j) if (depth[i] > depth[edge[i][j]]) parent_dist[i] = weight[i][j];
		}
	}
 
	//O(N) after make_depth
	void make_child(void) {
		child.resize(N);
		for (int i = 0; i < N; ++i) for (auto j : edge[i]) if (depth[i] < depth[j]) child[i].push_back(j);
 
		if(is_weighted) {
			child_dist.resize(N);
			for (int i = 0; i < N; ++i) for (int j = 0; j < edge[i].size(); ++j) if (depth[i] < depth[edge[i][j]]) child_dist[i].push_back(weight[i][j]);
		}
	}
 
	//O(NlogN) after make_depth
	void make_ancestor(void) {
		ancestor.resize(N,vector<int>(MAX_bit));
		for (int i = 0; i < N; ++i) ancestor[i][0] = i;
		for (int i = 0; i < N; ++i) for (auto j : edge[i]) if (depth[i] > depth[j]) ancestor[i][0] = j;
		for (int bit = 1; bit < MAX_bit; ++bit) for (int i = 0; i < N; ++i) ancestor[i][bit] = ancestor[ancestor[i][bit - 1]][bit - 1];
	}
 
	//O(N^2) after make_depth
	void make_descendant(void) {
		descendant.resize(N);
		for (int i = 0; i < N; ++i) descendant[i].push_back(i);
		for (int i = 0; i < N; ++i) for (auto j : edge[order[i]]) if (depth[order[i]] < depth[j]) for(auto k: descendant[j]) descendant[order[i]].push_back(k);
	}
 
	//O(logN) after make_ancestor
	int LCA(int l, int r) {
		if (depth[l] < depth[r]) swap(l, r);
		int diff = depth[l] - depth[r];
		for (int bit = 0; bit < MAX_bit; ++bit) if (diff & (1 << bit)) l = ancestor[l][bit];
		if(l==r) return l;
		for (int bit = MAX_bit - 1; 0 <= bit; --bit) if(ancestor[l][bit]!=ancestor[r][bit]) l = ancestor[l][bit], r = ancestor[r][bit];
		return ancestor[l][0];
	}
 
	//O(N) after make_child and make_parent
	void make_euler_tour(void){
        dfs2(order[N-1]);
		idxl.resize(N);
		idxr.resize(N);
		for(int i = 0; i < euler_tour.size(); ++i) idxr[euler_tour[i]] = i;
		for(int i = euler_tour.size()-1; 0 <= i; --i) idxl[euler_tour[i]] = i;
		return;
	}
 
    //for make_euler_tour
	void dfs2(int from, int prev = -1){
		euler_tour.push_back(from);
        if(is_weighted) euler_tour_dist.push_back(parent_dist[from]);
 
        for(int i = 0; i < child[from].size(); ++i){
            int to = child[from][i];
            
            dfs2(to,from);            
 
    		euler_tour.push_back(from);
            if(is_weighted) euler_tour_dist.push_back(-child_dist[from][i]);
        }
	}
 
};
 
//depth,dist
//https://atcoder.jp/contests/abc126/tasks/abc126_d
 
//LCA
//https://atcoder.jp/contests/abc014/tasks/abc014_4
 
//child
//https://atcoder.jp/contests/abc133/tasks/abc133_e

int main() {
    ll N; cin >> N;
    Tree<int> tree(N);
    vector<vector<pair<int,ll>>> edge(N);
    for(int i = 0; i < N-1; ++i) {
        int u,v,w;
        cin >> u >> v >> w;
        u--,v--;
        edge[u].push_back({v,w});
        edge[v].push_back({u,w});
        tree.make_edge(v,u);
        tree.make_edge(u,v);
    }
    tree.make_depth(0);
    tree.make_parent();
    vector<ll> scale(N,1); 
    for(auto idx:tree.order){
        if(idx) scale[tree.parent[idx]] += scale[idx];
    }
    ll ans = 0;
    for(int i = 0; i < N; ++i){
        for(auto e:edge[i]){
            ll s = min(scale[i],scale[e.first]);
            ans += (N-s)*s*e.second;
        }
    }
    cout << ans << endl;
}
0