結果

問題 No.806 木を道に
コンテスト
ユーザー face4
提出日時 2019-03-22 21:32:46
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
WA  
実行時間 -
コード長 989 bytes
コンパイル時間 1,071 ms
コンパイル使用メモリ 86,780 KB
実行使用メモリ 9,020 KB
最終ジャッジ日時 2024-09-19 02:52:58
合計ジャッジ時間 3,005 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge2
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 WA * 2
other WA * 27
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:44:19: warning: 'cost' may be used uninitialized [-Wmaybe-uninitialized]
   44 |     cout << n-1 + cost << endl;
      |                   ^~~~
main.cpp:33:9: note: 'cost' was declared here
   33 |     int cost;
      |         ^~~~
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:32:12:
/home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/stl_pair.h:535:11: warning: 't' 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:19:9: note: 't' was declared here
   19 |     int t;
      |         ^

ソースコード

diff # 

#include<iostream>
#include<vector>
#include<queue>
using namespace std;

int main(){
    int n;
    cin >> n;
    vector<int> v[n];
    int a, b;
    for(int i = 0; i < n-1; i++){
        cin >> a >> b;
        a--, b--;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    vector<bool> visit(n, 0);
    queue<int> q;
    int t;
    q.push(0);
    while(!q.empty()){
        int x = q.front();  q.pop();
        if(visit[x])    continue;
        t = x;
        visit[x] = true;
        for(int next : v[x]){
            if(!visit[next])    q.push(x);
        }
    }
    visit.resize(n, 0);
    queue<pair<int,int>> pq;
    pq.push({t, 0});
    int cost;
    while(!pq.empty()){
        auto x = pq.front(); pq.pop();
        int i = x.first;
        if(visit[i])    continue;
        cost = x.second;
        visit[i] = true;
        for(int next : v[i]){
            if(!visit[next])    pq.push({next, cost+1});
        }
    }
    cout << n-1 + cost << endl;
    return 0;
}
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