#421763 (C++14) No.763 Noelちゃんと木遊び

提出ソース

結果

問題	No.763 Noelちゃんと木遊び
ユーザー	ningenMe
提出日時	2020-01-27 05:41:23
言語	C++14 (gcc 12.3.0 + boost 1.83.0)
結果	AC
実行時間	99 ms / 2,000 ms
コード長	9,590 bytes
コンパイル時間	2,170 ms
コンパイル使用メモリ	179,256 KB
実行使用メモリ	21,248 KB
最終ジャッジ日時	2024-09-14 11:46:15
合計ジャッジ時間	5,068 ms
ジャッジサーバーID （参考情報）	judge2 / judge4

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テストケース

テストケース表示

入力	結果	実行時間実行使用メモリ
testcase_00	AC	87 ms 21,248 KB
testcase_01	AC	33 ms 6,912 KB
testcase_02	AC	81 ms 11,776 KB
testcase_03	AC	52 ms 9,088 KB
testcase_04	AC	37 ms 7,424 KB
testcase_05	AC	51 ms 8,832 KB
testcase_06	AC	99 ms 13,568 KB
testcase_07	AC	97 ms 13,312 KB
testcase_08	AC	55 ms 9,344 KB
testcase_09	AC	36 ms 7,296 KB
testcase_10	AC	15 ms 5,376 KB
testcase_11	AC	99 ms 13,824 KB
testcase_12	AC	85 ms 12,672 KB
testcase_13	AC	88 ms 12,544 KB
testcase_14	AC	76 ms 11,520 KB
testcase_15	AC	49 ms 8,960 KB
testcase_16	AC	9 ms 5,376 KB
testcase_17	AC	51 ms 9,088 KB
testcase_18	AC	99 ms 13,824 KB
testcase_19	AC	87 ms 12,800 KB
testcase_20	AC	86 ms 12,800 KB

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ソースコード

raw source code

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
 
#define ALL(obj) (obj).begin(),(obj).end()
#define SPEED cin.tie(0);ios::sync_with_stdio(false);
 
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> multivector(size_t N,T init){return vector<T>(N,init);}
template <class... T> auto multivector(size_t N,T... t){return vector<decltype(multivector(t...))>(N,multivector(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;}
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 nodeNum;
	int isWeighted;
	int maxBit;
	int idx;
	vector<vector<int>> edge;
	vector<vector<T>> weight;
	vector<int> depth;
	vector<int> order;
	vector<T> dist;
	
	vector<int> parent;
	vector<T> parentDist;
	
	vector<vector<int>> child;
	vector<vector<T>> childDist;
 
	vector<vector<int>> ancestor;
	vector<vector<int>> descendant;
	
	vector<int> eulerTour;
    vector<T> eulerTourDist;
	vector<int> eulerTourIdxL;
	vector<int> eulerTourIdxR;
    vector<int> eulerTourDive,eulerTourFloat;
    vector<T> eulerTourDiveDist,eulerTourFloatDist;
	vector<int> eulerTourDiveIdxL,eulerTourFloatIdxL;
	vector<int> eulerTourDiveIdxR,eulerTourFloatIdxR;
 
	Tree(const int nodeNum, const int isWeighted = 0, const int maxBit = 20) : 
	nodeNum(nodeNum),
	isWeighted(isWeighted),
	maxBit(maxBit),
	edge(nodeNum),
	depth(nodeNum),
	order(nodeNum)
	{
		if(isWeighted) weight.resize(nodeNum);
		if(isWeighted) dist.resize(nodeNum);
	}
 
	//O(1) anytime
	void makeEdge(const int& from, const int& to, const T& w = 0) {
		edge[from].push_back(to);
		if(isWeighted)	weight[from].push_back(w);
	}
 
	//O(N) anytime
	void makeDepth(const int root) {
		depth[root] = 0;
		if(isWeighted) dist[root] = 0;
		idx = 0;
		dfs1(root);
		order[idx++] = root;
	}
 
    //for makeDepth
	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(isWeighted) dist[to] = dist[from] + weight[from][i];
			dfs1(to,from);
			order[idx++] = to;
		}
	}
 
    //O(N) anytime
	int diameter(void){
		makeDepth(0);
		int tmp = max_element(depth.begin(), depth.end()) - depth.begin();
		makeDepth(tmp);
		return *max_element(depth.begin(), depth.end());
	}
 
	//O(N) after makeDepth
	void makeParent(void) {
		parent.resize(nodeNum);
		iota(parent.begin(),parent.end(),0);
		for (int i = 0; i < nodeNum; ++i) for (auto j : edge[i]) if (depth[i] > depth[j]) parent[i] = j;
 
		if(isWeighted) {
			parentDist.resize(nodeNum);
			for (int i = 0; i < nodeNum; ++i) for (int j = 0; j < edge[i].size(); ++j) if (depth[i] > depth[edge[i][j]]) parentDist[i] = weight[i][j];
		}
	}
 
	//O(N) after makeDepth
	void makeChild(void) {
		child.resize(nodeNum);
		for (int i = 0; i < nodeNum; ++i) for (auto j : edge[i]) if (depth[i] < depth[j]) child[i].push_back(j);
 
		if(isWeighted) {
			childDist.resize(nodeNum);
			for (int i = 0; i < nodeNum; ++i) for (int j = 0; j < edge[i].size(); ++j) if (depth[i] < depth[edge[i][j]]) childDist[i].push_back(weight[i][j]);
		}
	}
 
	//O(NlogN) after makeDepth
	void makeAncestor(void) {
		ancestor.resize(nodeNum,vector<int>(maxBit));
		for (int i = 0; i < nodeNum; ++i) ancestor[i][0] = i;
		for (int i = 0; i < nodeNum; ++i) for (auto j : edge[i]) if (depth[i] > depth[j]) ancestor[i][0] = j;
		for (int bit = 1; bit < maxBit; ++bit) for (int i = 0; i < nodeNum; ++i) ancestor[i][bit] = ancestor[ancestor[i][bit - 1]][bit - 1];
	}
 
	//O(N^2) after makeDepth
	void makeDescendant(void) {
		descendant.resize(nodeNum);
		for (int i = 0; i < nodeNum; ++i) descendant[i].push_back(i);
		for (int i = 0; i < nodeNum; ++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 makeAncestor
	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 < maxBit; ++bit) if (diff & (1 << bit)) l = ancestor[l][bit];
		if(l==r) return l;
		for (int bit = maxBit - 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 makeChild and makeParent
	void makeEulerTour(void){
        dfs2(order[nodeNum-1]);
		eulerTourIdxL.resize(nodeNum);
		eulerTourIdxR.resize(nodeNum);
		for(int i = 0; i < eulerTour.size(); ++i) eulerTourIdxR[eulerTour[i]] = i;
		for(int i = eulerTour.size()-1; 0 <= i; --i) eulerTourIdxL[eulerTour[i]] = i;
		return;
	}
 
    //for makeEulerTour
	void dfs2(int from, int prev = -1){
		eulerTour.push_back(from);
        if(isWeighted) eulerTourDist.push_back(parentDist[from]);
 
        for(int i = 0; i < child[from].size(); ++i){
            int to = child[from][i];            
            dfs2(to,from);            
    		eulerTour.push_back(from);
            if(isWeighted) eulerTourDist.push_back(-childDist[from][i]);
        }
	}

	//O(NlogN) after makeEulerTour
	void makeEulerTourEdge(void) {
		eulerTourDive.push_back(order[nodeNum-1]);
		if(isWeighted) eulerTourDiveDist.push_back(0);
		for(int i = 1; i < eulerTour.size(); ++i) {
			int l = eulerTour[i-1];
			int r = eulerTour[i];
			if(depth[l] < depth[r]) {
				eulerTourDive.push_back(i);
				if(isWeighted) eulerTourDiveDist.push_back(eulerTourDist[i]);
			}
			else {
				eulerTourFloat.push_back(i);
				if(isWeighted) eulerTourFloatDist.push_back(eulerTourDist[i]);
			}
		}
		eulerTourDiveIdxL.resize(nodeNum);
		eulerTourDiveIdxR.resize(nodeNum);
		eulerTourFloatIdxL.resize(nodeNum);
		eulerTourFloatIdxR.resize(nodeNum);
		for(int i = 0; i < nodeNum; ++i) {
			int l = eulerTourIdxL[i];
			int r = eulerTourIdxR[i];
			eulerTourDiveIdxL[i]  =  upper_bound(eulerTourDive.begin() ,eulerTourDive.end() ,l) - eulerTourDive.begin()     ;
			eulerTourDiveIdxR[i]  = (upper_bound(eulerTourDive.begin() ,eulerTourDive.end() ,r) - eulerTourDive.begin())  -1;
			eulerTourFloatIdxL[i] =  upper_bound(eulerTourFloat.begin(),eulerTourFloat.end(),l) - eulerTourFloat.begin()    ;
			eulerTourFloatIdxR[i] = (upper_bound(eulerTourFloat.begin(),eulerTourFloat.end(),r) - eulerTourFloat.begin()) -1;
			eulerTourDiveIdxR[i]  = max(eulerTourDiveIdxL[i]-1 ,eulerTourDiveIdxR[i]);
			eulerTourFloatIdxR[i] = max(eulerTourFloatIdxL[i]-1,eulerTourFloatIdxR[i]);
		}
	}
		// iの部分木の頂点に加算するとき
		// [ eulerTourIdxL[i]  ,eulerTourIdxR[i]  ]に　+val
		// [i]の頂点クエリ
		// [eulerTourIdxL[i],eulerTourIdxL[i]]

		// iの部分木の辺に加算するとき
		// [ eulerTourDiveIdxL[i]  ,eulerTourDiveIdxR[i]  ]に　+val
		// [ eulerTourFloatIdxL[i] ,eulerTourFloatIdxR[i] ]に　-val
		// [0,i]のパスクエリ
		// [ 0, eulerTourDiveIdxL[i] ) + [0, eulerTourFloatIdxL[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

//diameter
//https://atcoder.jp/contests/agc033/tasks/agc033_c

//eulerTour
//https://yukicoder.me/problems/no/900



int main() {
	int N; cin >> N;
	Tree<> tree(N);
	corner(N==1,1);
	for(int i = 0; i < N-1; ++i){
		int u,v; cin >> u >> v;
		u--,v--;
		tree.makeEdge(u,v);
		tree.makeEdge(v,u);
	}
	vector<int> dp1(N,1),dp2(N,0);
	tree.makeDepth(0);
	tree.makeChild();
	for(int pa:tree.order){
		int sum0 = 0,sum1 = 0,sum2 = 0,m = tree.child[pa].size();
		for(int& ch:tree.child[pa]) sum1 += dp1[ch];
		for(int& ch:tree.child[pa]) sum2 += dp2[ch];
		for(int& ch:tree.child[pa]) sum0 += max(dp1[ch],dp2[ch]);
		chmax(dp1[pa],sum1 - m + 1);
		chmax(dp1[pa],sum2 + 1);
		chmax(dp1[pa],sum0);
		chmax(dp2[pa],sum1);
		chmax(dp2[pa],sum2);
		chmax(dp2[pa],sum0);
	}
	cout << max(dp1[0],dp2[0]) << endl;


    return 0;
}