Submission #714121

#	Time	Username	Problem	Language	Result	Execution time	Memory
714121		william950615	Commuter Pass (JOI18_commuter_pass)	C++14	0 / 100	494 ms	40136 KiB

commuter_pass

#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define mkp make_pair
#define MEM(x) memset(x, 0, sizeof(x))
#define SZ(x) int(x.size())
#define ALL(x) begin(x), end(x)
#define REP(i,n) for( int i = 0; i < n; ++i )
#define FOR(i,a,b) for( int i = (a); i <= b; ++i )
#define RFOR(i,a,b) for( int i = (a); i >= b; --i )
#define EB emplace_back
#define EP emplace


#ifdef DEBUG
	template<typename T> void _DO(T&&x){cerr << x << '\n'}
	template<typename A, typename ...B> void _OD(A&&a, B&&...b){cerr << a <<','; _DO(b...);};
	#define de(...) do{\
		fprintf(stderr, "%s-%d (%s):", __func__, __LINE__, #__VA_ARGS__);\
		_DO(__VA_ARGS__);\
	}while(0);
#else
	#define de(...)
#endif
typedef long long ll;
typedef pair<int,int> pii;
typedef array<ll, 3> arr;
template<typename T> 
using V = vector<T>;

constexpr int mxN = 3e5+1;
constexpr ll inf = 1e18;

vector<arr> graph[ mxN ];

struct ShortPath {
	int st;
	ll dis[ mxN ];


	void DO() {
		priority_queue< arr, V<arr>, greater<arr>> pq;
		pq .EP( arr{0, st, st} );
		while( !pq.empty() ) {
			auto a = pq.top(); pq.pop();
			if( dis[ a[1] ] != inf ) continue;
			dis[ a[1] ] = a[0];


			for( auto &i : graph[ a[1] ] ) {
				if( dis[ i[1] ] != inf ) continue;
				pq.EP( arr{ a[0]+i[0], i[1], a[1] });
			}
		}
	};
	
	ll operator() (int t ) {
		return dis[ t ] ;
	};
	
	ShortPath( int _st ) {
		st = _st;
		for( auto &i : dis ) i = inf;
		DO();
	};
};


inline void solve() {
	int N, M; cin >> N >> M;
	int s, t; cin >> s >> t;
	int u, v; cin >> u >> v;
	REP(edge, M ){
		int a, b, c;
		cin >> a >> b >> c;
		graph[ a ].EB( arr{c,b,edge+1} );
		graph[ b ].EB( arr{c,a,edge+1} );
	}


	// make shortest path
	ShortPath froms(s), fromv(v), fromt(t), fromu(u);
	ll ans = fromu(v)*2;


	ans = min( {
			froms(u) + fromt(v) + fromu(v) - froms(t),
			froms(v) + fromt(u) + fromu(v) - froms(t),
			ans
			});
	// check if (u, v) is on the shortest path

	/*
	for( int i = 1; i <= N; ++i ) {
		cout << froms(i) << ' ';
	}
	cout << '\n';
	for( int i = 1; i <= N; ++i ) {
		cout << fromt(i) << ' ';
	}
	cout << '\n';
	*/
	cout << ans / 2<< '\n';
}

int main () {
	int T = 1;	
#ifdef Local
	cin >> T;
#endif
	while(T--) solve();
}

• Subtask 1: 0 / 16
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45