結果
問題 | No.1424 Ultrapalindrome |
ユーザー |
|
提出日時 | 2021-03-12 22:40:03 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 41 ms / 2,000 ms |
コード長 | 3,040 bytes |
コンパイル時間 | 2,035 ms |
コンパイル使用メモリ | 198,888 KB |
最終ジャッジ日時 | 2025-01-19 15:19:18 |
ジャッジサーバーID (参考情報) |
judge2 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 29 |
ソースコード
#include <bits/stdc++.h>using namespace std;// #include <atcoder/all>// using namespace atcoder;using ll = long long;using ld = long double;using vi = vector<int>;using vvi = vector<vector<int>>;using vvvi = vector<vector<vector<int>>>;using vl = vector<ll>;using vvl = vector<vector<ll>>;using vvvl = vector<vector<vector<ll>>>;using vs = vector<string>;using vb = vector<bool>;#define FOR(i, m, n) for (int i = (m); i < (n); i++)#define FORR(i, m, n) for (int i = (m); i >= (n); i--)#define REP(i, n) FOR(i, 0, (n))#define REPR(i, n) FORR(i, (n) - 1, 0)#define REP1(i, n) FOR(i, 1, (n) + 1)#define REPS(c, s) for (char c : s)#define ALL(c) (c).begin(), (c).end()#define SORT(c) sort(ALL(c))#define REV(c) reverse(ALL(c))#define sz(v) (int)v.size()#define endl '\n'template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}template<class T> inline void prn(vector<T>& v) {int n = sz(v); REP(i, n) cout << v[i] << ' ';}template<class T> inline void printv(vector<T>& v) {int n = sz(v); REP(i, n) cout << v[i] << (i == n - 1 ? endl : ' ');}template<class T> inline void printvv(vector<vector<T>>& v) {for (auto u : v) printv(u);}template<class T> inline void printvm(vector<T>& v) {int n = sz(v); REP(i, n) cout << v[i].val() << (i == n - 1 ? endl : ' ');}template<class T> inline void printvvm(vector<vector<T>>& v) {for (auto u : v) printvm(u);}template<class T> inline void printlnv(vector<T>& v) {int n = sz(v); REP(i, n) cout << v[i] << endl;}const int MOD = 1000000007;const int INF = 1000000001;const ll LINF = 1000000001000000001LL;void solve();int main() {ios::sync_with_stdio(false);cin.tie(nullptr);cout << fixed << setprecision(numeric_limits<double>::max_digits10);solve();return 0;}void solve() {int n;cin >> n;vvi g(n, vi());int a, b;REP(i, n - 1) {cin >> a >> b;a--;b--;g[a].emplace_back(b);g[b].emplace_back(a);}if (n <= 4) {cout << "Yes" << endl;return;}int c = -1;REP(i, n) {if (sz(g[i]) > 2) {if (c != -1) {cout << "No" << endl;return;} else {c = i;}}}if (c == -1) {cout << "Yes" << endl;return;}int ans = -1;function<bool(int, int, int)> dfs = [&](int c, int p, int d) {if (sz(g[c]) == 1) {if (ans != -1 and ans != d) return false;else {ans = d;return true;}}bool ret = true;for (auto e : g[c]) {if (e == p) continue;ret &= dfs(e, c, d + 1);}return ret;};cout << (dfs(c, -1, 0) ? "Yes" : "No") << endl;// cout << 100000 << endl;// REP(i, 99999) cout << "1 " << i + 1 << endl;}