結果

問題 No.1424 Ultrapalindrome
コンテスト
ユーザー GRMN
提出日時 2021-05-02 22:02:41
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 83 ms / 2,000 ms
コード長 1,834 bytes
コンパイル時間 4,116 ms
コンパイル使用メモリ 257,972 KB
最終ジャッジ日時 2025-01-21 06:03:39
ジャッジサーバーID
（参考情報） 		judge3 / judge3
このコードへのチャレンジ
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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
In file included from /usr/include/x86_64-linux-gnu/c++/13/bits/c++allocator.h:33,
                 from /usr/include/c++/13/bits/allocator.h:46,
                 from /usr/include/c++/13/string:43,
                 from /usr/include/c++/13/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:52,
                 from main.cpp:1:
In member function ‘void std::__new_allocator<_Tp>::construct(_Up*, _Args&& ...) [with _Up = int; _Args = {const int&}; _Tp = int]’,
    inlined from ‘static void std::allocator_traits<std::allocator<_CharT> >::construct(allocator_type&, _Up*, _Args&& ...) [with _Up = int; _Args = {const int&}; _Tp = int]’ at /usr/include/c++/13/bits/alloc_traits.h:538:17,
    inlined from ‘void std::deque<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = int; _Alloc = std::allocator<int>]’ at /usr/include/c++/13/bits/stl_deque.h:1543:30,
    inlined from ‘void std::queue<_Tp, _Sequence>::push(const value_type&) [with _Tp = int; _Sequence = std::deque<int, std::allocator<int> >]’ at /usr/include/c++/13/bits/stl_queue.h:286:20,
    inlined from ‘int main()’ at main.cpp:50:13:
/usr/include/c++/13/bits/new_allocator.h:191:11: warning: ‘id’ may be used uninitialized [-Wmaybe-uninitialized]
  191 |         { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
main.cpp: In function ‘int main()’:
main.cpp:33:15: note: ‘id’ was declared here
   33 |     int tmp=0,id;
      |               ^~

ソースコード

diff # 

#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
#define rep(i,n) for (int i = 0; i < (n); i++)
#define REP(i,a,b) for(int i=(a);i<(b);i++)
#define all(v) begin(v),end(v)
#define rall(v) rbegin(v),rend(v)
#define fi first
#define se second
#define re0 return 0
template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
constexpr ll inf = 2e9;
constexpr ll llinf = 9e18;
//constexpr ll MOD = 998244353;
constexpr ll MOD = 1000000007;
const double pai=acos(-1);

int main() {
    //cout<<fixed<<setprecision(15);
    int n;cin>>n;
    vector<vector<int>> g(n);
    rep(i,n-1){
        int a,b;cin>>a>>b;
        a--;b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    int tmp=0,id;
    rep(i,n){
        int a=g[i].size();
        if(a>tmp){
            tmp=a;
            id=i;
        }
    }
    if(tmp==1||tmp==2){
        cout<<"Yes"<<endl;
        re0;
    }
    //cout<<id<<endl;
    vector<int> vec(n),vec1(n);
    vector<int> d(n,-1);
    queue<int> que;
    d[id]=0;
    que.push(id);
    while(!que.empty()){
        int v=que.front();que.pop();
        for(auto u:g[v]){
            if(d[u]!=-1)continue;
            d[u]=d[v]+1;
            que.push(u);
            if(g[u].size()==1)vec[u]=1,vec1[v]++;
        }
    }
    //rep(i,n)cout<<d[i]<<endl;
    set<int> st;
    rep(i,n){
        if(vec[i])st.insert(d[i]);
    }
    bool ok=true;
    if(st.size()!=1)ok=false;
    rep(i,n){
        for(auto u:g[i]){
            if(vec[i]&&vec1[u]>1&&u!=id)ok=false;
        }
    }
    if(ok)cout<<"Yes"<<endl;
    else cout<<"No"<<endl;
}
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