結果
| 問題 |
No.1424 Ultrapalindrome
|
| コンテスト | |
| ユーザー |
 hirono999
|
| 提出日時 | 2021-03-12 22:15:20 |
| 言語 | C++17(gcc12) (gcc 12.3.0 + boost 1.87.0) |
| 結果 |
WA
(最新)
AC
(最初)
|
| 実行時間 | - |
| コード長 | 10,141 bytes |
| コンパイル時間 | 14,542 ms |
| コンパイル使用メモリ | 317,924 KB |
| 最終ジャッジ日時 | 2025-01-19 14:57:22 |
|
ジャッジサーバーID （参考情報） |
judge1 / judge2 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 28 WA * 1 |
ソースコード
#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);
}
vec root;
rep(i, N) if(len(G[i]) == 1) root.pb(i);
set<ll> st;
ll leaf = 0;
auto dfs = [&](auto &&self, ll d, ll cur, ll par = -1)->void {
bool is_leaf = true;
for(auto e : G[cur]){
if(e.to == par) continue;
self(self, d + 1, e.to, e.from);
is_leaf = false;
}
if(is_leaf) st.insert(d), ++leaf;
};
rep(_, 100){
dfs(dfs, 0, root[rand() % len(root)]);
}
print(len(st) == 1 ? "Yes" : "No");
return 0;
}