結果

問題 No.1424 Ultrapalindrome
コンテスト
ユーザー nuxxpp
提出日時 2021-03-14 12:55:00
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 41 ms / 2,000 ms
コード長 1,833 bytes
コンパイル時間 3,328 ms
コンパイル使用メモリ 164,544 KB
実行使用メモリ 10,744 KB
最終ジャッジ日時 2024-11-06 02:40:10
合計ジャッジ時間 5,688 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge3
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
sample AC * 3
other AC * 29
権限があれば一括ダウンロードができます
コンパイルメッセージ
main.cpp: In function 'int main()':
main.cpp:81:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17' [-Wc++17-extensions]
   81 |     auto [ind, dis]  = que.front(); que.pop();
      |          ^
In file included from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/stl_algobase.h:64,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/string:50,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/locale_classes.h:40,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/ios_base.h:41,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/ios:42,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/ostream:38,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/iostream:39,
                 from main.cpp:1:
In constructor 'constexpr std::pair<_T1, _T2>::pair(_U1&&, _U2&&) [with _U1 = int&; _U2 = int; typename std::enable_if<(std::_PCC<true, _T1, _T2>::_MoveConstructiblePair<_U1, _U2>() && std::_PCC<true, _T1, _T2>::_ImplicitlyMoveConvertiblePair<_U1, _U2>()), bool>::type <anonymous> = true; _T1 = int; _T2 = int]',
    inlined from 'int main()' at main.cpp:79:12:
/home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/stl_pair.h:535:11: warning: 's' may be used uninitialized [-Wmaybe-uninitialized]
  535 |         : first(std::forward<_U1>(__x)), second(std::forward<_U2>(__y)) { }
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
main.cpp: In function 'int main()':
main.cpp:56:15: note: 's' was declared here
   56 |   int tc = 0, s;
      |               ^

ソースコード

diff # 

#include <iostream>
#include <iomanip>
#include <cstdio>
#include <queue>
#include <cstring>
#include <vector>
#include <map>
#include <algorithm>
#include <cctype>
#include <cmath>
#include <bitset>
#include <set>
#include <deque>
#include <stack>
#include <atcoder/all>

using namespace std;

#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define RREP(i,n) for(int i=n-1;i>=0;i--)
#define FOR(i,k,n) for(int i=(k);i<(int)(n);i++)
#define all(i,n) (i),(i+n)

int dx4[4]={1,0,-1,0};
int dy4[4]={0,-1,0,1};
int dx8[8]={1,0,-1,1,-1,1,0,-1};
int dy8[8]={1,1,1,0,0,-1,-1,-1};

typedef pair<int, int> P;
typedef pair<string, int> SP;
typedef long long ll;
typedef pair<ll, ll> PLL;

const int INF = 1e9;
const ll LLINF = 1e18;
const int MAX_V = 1e6+1;
// const ll mod = 1e9 + 7;
//  cout << fixed << setprecision(10)
// --------------------------------------
int n;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin >> n;
  vector<int> g[n];

  int a, b;
  REP(i, n - 1) {
    cin >> a >> b;
    a--; b--;
    g[a].push_back(b);
    g[b].push_back(a);
  }

  int tc = 0, s;
  REP(i, n) {
    if(g[i].size() > 2) {
      tc++;
      s = i;
    }
  }

  if(tc == 0) {
    cout << "Yes" << endl;
    return 0;
  } else if(tc > 1) {
    cout << "No" << endl;
    return 0;
  }

  vector<int> onev;
  REP(i, n) {
    if(g[i].size() == 1) onev.push_back(i);
  }

  vector<int> d(n, -1);
  queue<P> que;
  que.push(P(s, 0));
  while(!que.empty()) {
    auto [ind, dis]  = que.front(); que.pop();
    d[ind] = dis;

    for(auto x: g[ind]) {
      if(d[x] == -1) {
        que.push(P(x, dis + 1));
      }
    }
  }

  bool f = true;
  int t = -1;
  REP(i, n) {
    if(g[i].size() == 1) {
      if(t != -1 && d[i] != t) {
        f = false;
      } else {
        t = d[i];
      }
    }
  }

  cout << (f ? "Yes" : "No") << endl;
}
0