結果

問題 No.1833 Subway Planning
ユーザー 👑 potato167potato167
提出日時 2022-02-04 22:17:24
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 664 ms / 4,000 ms
コード長 2,807 bytes
コンパイル時間 2,150 ms
コンパイル使用メモリ 216,220 KB
実行使用メモリ 32,552 KB
最終ジャッジ日時 2024-06-11 12:00:51
合計ジャッジ時間 11,041 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge1
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 2 ms
5,248 KB
testcase_01 AC 1 ms
5,376 KB
testcase_02 AC 2 ms
5,376 KB
testcase_03 AC 2 ms
5,376 KB
testcase_04 AC 166 ms
29,140 KB
testcase_05 AC 225 ms
29,292 KB
testcase_06 AC 211 ms
27,580 KB
testcase_07 AC 623 ms
28,524 KB
testcase_08 AC 620 ms
28,780 KB
testcase_09 AC 664 ms
29,160 KB
testcase_10 AC 274 ms
32,448 KB
testcase_11 AC 317 ms
32,432 KB
testcase_12 AC 302 ms
32,552 KB
testcase_13 AC 291 ms
32,328 KB
testcase_14 AC 202 ms
32,432 KB
testcase_15 AC 420 ms
32,168 KB
testcase_16 AC 561 ms
32,304 KB
testcase_17 AC 567 ms
31,744 KB
testcase_18 AC 533 ms
29,916 KB
testcase_19 AC 391 ms
31,616 KB
testcase_20 AC 251 ms
25,544 KB
testcase_21 AC 412 ms
29,048 KB
testcase_22 AC 340 ms
30,092 KB
testcase_23 AC 2 ms
5,376 KB
testcase_24 AC 2 ms
5,376 KB
testcase_25 AC 2 ms
5,376 KB
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 'void solve()':
main.cpp:77:44: warning: 'e' may be used uninitialized [-Wmaybe-uninitialized]
   77 |                         swap(seen[i],seen[e]);
      |                                            ^
main.cpp:41:15: note: 'e' was declared here
   41 |         int d,e,f=0;
      |               ^
In file included from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/x86_64-pc-linux-gnu/bits/c++allocator.h:33,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/allocator.h:46,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/string:41,
                 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/istream:38,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/sstream:38,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/complex:45,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/ccomplex:39,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/x86_64-pc-linux-gnu/bits/stdc++.h:54,
                 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 /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/alloc_traits.h:516:17,
    inlined from 'void std::deque<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = i

ソースコード

diff # 

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define _GLIBCXX_DEBUG
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll ILL=1167167167167167167;
const int INF=2100000000;
const ll mod=998244353;
#define rep(i,a) for (ll i=0;i<a;i++)
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}

bool g(vector<vector<pair<int,int>>> &G,int A,int B);

void solve();

//  rainy ~ 雨に打たれて ~
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int t=1;
	//cin>>t;
	rep(i,t) solve();
}

void solve(){
	int N;
	cin>>N;
	vector<vector<pair<int,int>>> G(N);
	int d,e,f=0;
	rep(i,N-1){
		int a,b,c;
		cin>>a>>b>>c;
		a--,b--;
		G[a].push_back({b,c});
		G[b].push_back({a,c});
		if(chmax(f,c)) d=a,e=b;
	}
	vector<int> seen(N);
	seen[d]=1;
	queue<int> q;
	q.push(d);
	while(!q.empty()){
		int y=q.front();
		q.pop();
		for(auto x:G[y]){
			if(x.first!=e&&seen[x.first]==0){
				seen[x.first]=1;
				q.push(x.first);
			}
		}
	}
	int A=0,B=0;
	rep(i,N){
		if(seen[i]) seen[i]=A,A++;
		else seen[i]=B-N,B++;
	}
	rep(i,N){
		if(seen[i]>=0){
			swap(seen[d],seen[i]);
			break;
		}
	}
	rep(i,N){
		if(seen[i]<0){
			swap(seen[i],seen[e]);
			break;
		}
	}
	vector<vector<pair<int,int>>> H(A),I(B);
	rep(i,N) for(auto x:G[i]){
		if(seen[i]<0&&seen[x.first]<0){
			I[seen[i]+N].push_back({seen[x.first]+N,x.second});
		}else if(seen[i]>=0&&seen[x.first]>=0){
			H[seen[i]].push_back({seen[x.first],x.second});
		}
	}
	int l=-1,r=f;
	while(r-l>1){
		int med=(l+r)/2;
		if(g(H,med,f-med)&g(I,med,f-med)){
			r=med;
		}else l=med;
	}
	cout<<r<<"\n";
}

bool g(vector<vector<pair<int,int>>> &G,int A,int B){
	int n=G.size();
	vector<int> order={0};
	vector<pair<int,int>> pare(n,{-1,-1});
	pare[0]={-2,-2};
	rep(i,n){
		int a=order[i];
		for(auto x:G[a]){
			if(pare[x.first].first==-1){
				pare[x.first]={a,x.second};
				order.push_back(x.first);
			}
		}
	}
	vector<int> dp(n,INF);
	rep(i,n-1){
		int a=order[n-i-1];
		if(pare[a].second>A){
			chmin(dp[a],pare[a].second);
		}
		if(dp[a]!=INF){
			chmin(dp[a],pare[a].second);
			if(dp[pare[a].first]!=INF) dp[pare[a].first]=-1;
			else dp[pare[a].first]=dp[a];
		}
	}
	return dp[0]>=B;
}
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