結果

問題 No.1424 Ultrapalindrome
ユーザー hirono999hirono999
提出日時 2021-03-12 22:07:36
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
WA  
実行時間 -
コード長 10,590 bytes
コンパイル時間 4,229 ms
コンパイル使用メモリ 259,972 KB
実行使用メモリ 22,356 KB
最終ジャッジ日時 2024-10-14 12:34:40
合計ジャッジ時間 6,105 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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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 2 ms
5,248 KB
testcase_01 AC 2 ms
5,248 KB
testcase_02 AC 1 ms
5,248 KB
testcase_03 AC 2 ms
5,248 KB
testcase_04 AC 2 ms
5,248 KB
testcase_05 WA -
testcase_06 AC 1 ms
5,248 KB
testcase_07 AC 1 ms
5,248 KB
testcase_08 WA -
testcase_09 AC 39 ms
11,776 KB
testcase_10 AC 41 ms
11,776 KB
testcase_11 AC 27 ms
9,216 KB
testcase_12 AC 37 ms
11,264 KB
testcase_13 AC 11 ms
5,632 KB
testcase_14 AC 35 ms
9,984 KB
testcase_15 AC 2 ms
5,248 KB
testcase_16 AC 24 ms
8,448 KB
testcase_17 AC 28 ms
9,488 KB
testcase_18 AC 18 ms
7,624 KB
testcase_19 AC 32 ms
9,600 KB
testcase_20 AC 9 ms
5,248 KB
testcase_21 AC 27 ms
8,704 KB
testcase_22 AC 16 ms
6,784 KB
testcase_23 AC 4 ms
5,248 KB
testcase_24 AC 8 ms
5,248 KB
testcase_25 AC 7 ms
5,248 KB
testcase_26 AC 41 ms
11,008 KB
testcase_27 WA -
testcase_28 AC 43 ms
22,356 KB
testcase_29 AC 47 ms
22,356 KB
testcase_30 AC 33 ms
15,664 KB
testcase_31 AC 36 ms
15,660 KB
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 # 

#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
constexpr long long INF = 1LL << 60;
double PI = acos(-1.0);
#define rep(i, n) for (ll i = 0; i < (n); ++i)
#define rep1(i, n) for (ll i = 1; i <= (n); ++i)
#define rrep(i, n) for (ll i = (n - 1); i >= 0; --i)
#define perm(c) sort(ALL(c));for(bool c##p=1;c##p;c##p=next_permutation(ALL(c)))
#define ALL(obj) (obj).begin(), (obj).end()
#define RALL(obj) (obj).rbegin(), (obj).rend()
#define pb push_back
#define to_s to_string
#define len(v) (ll)v.size()
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end())
#define print(x) cout << (x) << '\n'
#define drop(x) cout << (x) << '\n', exit(0)
#define debug(x) cout << #x << ": " << (x) << '\n'
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> P;
typedef tuple<ll, ll, ll> tpl;
typedef vector<ll> vec;
typedef vector<vector<ll>> vec2;
typedef vector<vector<vector<ll>>> vec3;
template<class S, class T> inline bool chmax(S &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class S, class T> inline bool chmin(S &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
inline ll msb(ll v) { return 1LL << (63 - __builtin_clzll(v)); }
inline ll devc(ll x, ll y) { return ceil(ld(x) / y); }
inline ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
inline ll lcm(ll a, ll b) { return a * (b / gcd(a, b)); }
 
struct IoSetup {
    IoSetup() {
        cin.tie(nullptr);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(10);
        cerr << fixed << setprecision(10);
    }
} iosetup;
 
template< typename T1, typename T2 >
ostream &operator << (ostream &os, const pair< T1, T2 > &p) {
    os << p.first << " " << p.second;
    return os;
}
 
template< typename T1, typename T2 >
istream &operator >> (istream &is, pair< T1, T2 > &p) {
    is >> p.first >> p.second;
    return is;
}
 
template< typename T1, typename T2, typename T3 >
ostream &operator << (ostream &os, const tuple< T1, T2, T3 > &t) {
    os << get<0>(t) << " " << get<1>(t) << " " << get<2>(t);
    return os;
}
 
template< typename T1, typename T2, typename T3 >
istream &operator >> (istream &is, tuple< T1, T2, T3 > &t) {
    is >> get<0>(t) >> get<1>(t) >> get<2>(t);
    return is;
}
 
template< typename T >
ostream &operator << (ostream &os, const vector< T > &v){
    for (int i = 0; i < (int)v.size(); ++i) {
        os << v[i] << (i + 1 != v.size() ? " " : "");
    }
    return os;
}
 
template< typename T >
istream &operator >>  (istream &is, vector< T > &v){
    for(T &in : v) is >> in;
    return is;
}

template< typename T >
ostream &operator << (ostream &os, const set< T > &st){
    int ct = 0;
    for(auto& s : st) cout << s << (++ct != st.size() ? " " : "");
    return os;
}

template <typename T>
constexpr set<T> &operator|= (set<T> &st1, const set<T> &st2) { 
    for(auto& s : st2) st1.insert(s);
    return st1; 
}

template <typename T>
constexpr set<T> &operator-= (set<T> &st1, const set<T> &st2) {
    for(auto& s : st2) if(st1.count(s)) st1.erase(s);
    return st1;
}

template <typename T>
constexpr set<T> &operator&= (set<T> &st1, const set<T> &st2) {
    auto itr = st1.begin();
    while(itr != st1.end()){
        if(!st2.count(*itr)) itr = st1.erase(itr);
        else ++itr;
    }
    return st1;
}

template <typename T>
constexpr set<T> operator| (const set<T> &st1, const set<T> &st2) {
    set<T> res = st1;
    res |= st2;
    return res;
}

template <typename T>
constexpr set<T> operator- (const set<T> &st1, const set<T> &st2) {
    set<T> res = st1;
    res -= st2;
    return res;
}

template <typename T>
constexpr set<T> operator& (const set<T> &st1, const set<T> &st2) {
    set<T> res = st1;
    res &= st2;
    return res;
}

/*---------------------------------    Tools    ------------------------------------------*/
template< typename T >
vector<T> cumsum(const vector<T> &X){
    vector<T> res(X.size() + 1, 0);
    for(int i = 0; i < X.size(); ++i) res[i + 1] += res[i] + X[i];
    return res;
}
 
template< typename S, typename T, typename F>
pair<T, T> bisearch(S left, T right, F f) {
    while(abs(right - left) > 1){
        T mid = (right + left) / 2;
        if(f(mid)) right = mid;
        else left = mid;
    }
    return {left, right};
}
 
template< typename S, typename T, typename F>
double trisearch(S left, T right, F f, int maxLoop = 90){
    double low = left, high = right;
    while(maxLoop--){
        double mid_left = high / 3 + low * 2 / 3;
        double mid_right = high * 2 / 3 + low / 3;
        if(f(mid_left) >= f(mid_right)) low = mid_left;
        else high = mid_right;
    }
    return (low + high) * 0.5;
}

template< typename F >
ll findMinimum(ll L, ll R, F f) { //[L, R)
    ll lo = L - 1, hi = R - 1;
    while (lo + 1 != hi) {
        ll mi = (lo + hi) / 2;
        if (f(mi) <= f(mi + 1)) hi = mi;
        else lo = mi;
    }
    return hi;
}

/*---------------------------------    Graph    ------------------------------------------*/
struct Graph {
    struct Edge {
        ll from, to, weight;
        Edge() : from(0), to(0), weight(0) {}
        Edge(ll f, ll t, ll w) : from(f), to(t), weight(w) {}
    };
    using Edges = vector<Edge>;

    vector<Edges> G;

    Graph() : G() {};

    Graph(int N) : G(N) {}

    Edges operator[](int k) const{
        return G[k];
    }

    ll size() const{
        return G.size();
    }

    void resize(int N){
        G.resize(N);
    }

    void add_edge(int a, int b, ll w = 1){
        G[a].emplace_back(a, b, w);
        G[b].emplace_back(b, a, w);
    }

    void add_arrow(int a, int b, ll w = 1){
        G[a].emplace_back(a, b, w);
    }

    //Topological_sort
    //!!return empty, if not DAG
    vector<ll> topological_sort() const;

    //Dijkstra and related
    vector<ll> dijkstra(ll s, bool restore = false) const;

    vector<ll> shortest_path(ll start, ll goal) const;

    //Bellman-Ford
    //!!return empty, if negative loop exists
    vector<ll> bellman_ford(ll s) const;

    //Warshall-Floyd
    vector<vector<ll>> Warshall_Floyd() const; 

    //Kruskal
    //!!Required UnionFind
    Graph Kruskal() const;

    //Tree Algorithms
    //Tree centroid
    vector<ll> treeCentroid() const;
};


vector<ll> Graph::dijkstra(ll s, bool restore) const{
    vector<ll> dist(G.size(), INF);
    priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>> que;
    dist[s] = 0;
    que.emplace(dist[s], s);

    vector<ll> prev(G.size(), -1);

    while(!que.empty()){
        ll cost, idx;
        tie(cost, idx) = que.top();
        que.pop();
        if(dist[idx] < cost) continue;
        for(auto &e : G[idx]){
            auto next_cost = cost + e.weight;
            if(dist[e.to] <= next_cost) continue;
            dist[e.to] = next_cost;

            if(restore) prev[e.to] = e.from;
            que.emplace(dist[e.to], e.to);
        }
    }
    if(restore) return prev;
    return dist;
}

vector<ll> Graph::shortest_path(ll start, ll goal) const{
    vector<ll> prev = dijkstra(start, true);
    vector<ll> path;
    for (int cur = goal; cur != -1; cur = prev[cur]) path.push_back(cur);
    reverse(path.begin(), path.end());
    if (path.front() != start) return {};
    return path;
}

vector<ll> Graph::bellman_ford(ll s) const{
    vector<ll> dist(G.size(), INF);
    dist[s] = 0;
    for (ll i = 0; i < G.size(); ++i) {
        for (ll j = 0; j < G.size(); ++j){
            for (auto& e : G[j]) {
                if(dist[e.from] == INF) continue;
                bool res = chmin(dist[e.to], dist[e.from] + e.weight);
                if (i == G.size() - 1 and res) return {};
            }
        }
    }
    return dist;
}

vector<vector<ll>> Graph::Warshall_Floyd() const {
    int N = G.size();
    vector<vector<ll>> d(N, vector<ll>(N));

    rep(i, N) rep(j, N) {
        if (i == j) d[i][j] = 0;
        else d[i][j] = INF;
    }

    rep(i, N) for (auto &e : G[i]) d[i][e.to] = e.weight;
    rep(k, N) rep(i, N) rep(j, N) {
        if (d[i][k] == INF or d[k][j] == INF) continue;
        d[i][j] = min(d[i][j], d[i][k]+d[k][j]);
    }
    return d;
}

vector<ll> Graph::topological_sort() const{
    vector<ll> ans;
    int N = G.size();
    vector<int> ind(N);
    rep(i, N) for (auto &e : G[i]) ind[e.to]++;
    queue<int> que;
    rep(i, N) if (!ind[i]) que.push(i);
    while(!que.empty()){
        int now  = que.front();
        ans.pb(now);
        que.pop();
        for(auto& e : G[now]) {
            ind [e.to]--;
            if(!ind[e.to]) que.push(e.to);
        }
    }
    if (ans.size() != N) return {};
    return ans;
}

vector<ll> Graph::treeCentroid() const{
    int N = G.size();
    vector<ll> centroid, val(N);
    auto dfs = [&](auto&& self, int cur, int par)->void {
        bool is_centroid = true;
        val[cur] = 1;
        for(auto &e : G[cur]){
            if(e.to == par) continue;
            self(self, e.to, cur);
            val[cur] += val[e.to];
            if(val[e.to] > N / 2) is_centroid = false;
        }
        if(N - val[cur] > N / 2) is_centroid = false;
        if(is_centroid) centroid.push_back(cur);
    };
    dfs(dfs, 0, -1);
    return centroid;
}

// #include <atcoder/all>
// using namespace atcoder;
constexpr long long MOD = 1000000007;
/*------------------------------- Main Code Here -----------------------------------------*/
 
int main()
{
    ll N;
    cin >> N;
    vector<P> X(N - 1);
    cin >> X;

    Graph G(N);
    for(auto [a, b] : X){
        --a, --b;
        G.add_edge(a, b);
    }

    auto ret = G.treeCentroid();

    set<ll> st;
    ll leaf = 0;
    auto dfs = [&](auto &&self, ll d, ll cur, ll par = -1, ll f = -1)->void {
        bool is_leaf = true;
        for(auto e : G[cur]){
            if(e.to == par) continue;
            if(e.to == f) continue;
            self(self, d + 1, e.to, e.from);
            is_leaf = false;
        }
        if(is_leaf) st.insert(d), ++leaf;
    };

    if(len(ret) == 1){
        dfs(dfs, 0, ret[0], -1, -1);
        drop(len(st) == 1 ? "Yes" : "No");
    }


    dfs(dfs, 0, ret[0], -1, ret[1]);

    if(len(st) != 1) drop("No");

    set<ll> checker;

    ll x = *st.begin();
    if(leaf >= 2) checker.insert(2 * x);

    st.clear();
    leaf = 0;

    dfs(dfs, 0, ret[1], -1, ret[0]);
    if(len(st) != 1) drop("No");

    ll y = *st.begin();
    if(leaf >= 2) checker.insert(2 * y);

    checker.insert(x + y + 1);

    // debug(checker);

    drop(len(checker) == 1 ? "Yes" : "No");

    return 0;
}
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