Submission #237045

#	Time	Username	Problem	Language	Result	Execution time	Memory
237045		anubhavdhar	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	1396 ms	27108 KiB

commuter_pass

#include<bits/stdc++.h>

#define ll long long int
#define pb push_back
#define mp make_pair
#define FOR(i,n) for(i=0;i<(n);++i)
#define FORe(i,n) for(i=1;i<=(n);++i)
#define FORr(i,a,b) for(i=(a);i<(b);++i)
#define FORrev(i,n) for(i=(n);i>=0;--i)
#define F0R(i,n) for(int i=0;i<(n);++i)
#define F0Re(i,n) for(int i=1;i<=(n);++i)
#define F0Rr(i,a,b) for(ll i=(a);i<(b);++i)
#define F0Rrev(i,n) for(int i=(n);i>=0;--i)
#define ii pair<ll,ll>
#define vi vector<ll>
#define vii vector<ii>
#define ff first 
#define ss second
#define cd complex<double>
#define vcd vector<cd>
#define ldd long double
#define dbgLine cout<<"Line : "<<__LINE__<<'\n'
#define all(x) (x).begin(),(x).end()

using namespace std;

const short int __PRECISION = 10;

const ll MOD = 1e9+7;
const ll INF = 1e17 + 1101;
const ll LOGN = 17;
const ll MAXN = 1e5+5;
const ll ROOTN = 320;

const ldd PI = acos(-1);
const ldd EPS = 1e-7;

int N, M, U, V, S, T;
ll d[2][MAXN], ans;
ii dis[2][MAXN];
vii g[MAXN];


inline void Dijkstra(int s)
{
	int m = (s == U ? 0 : 1);
	set<ii> x;
	F0Re(i, N)
		d[m][i] = INF;
	d[m][s] = 0;
	x.insert(mp(0, s));
	while(!x.empty())
	{
		int a = (*x.begin()).ss;
		x.erase(x.begin());
		for(ii p : g[a])
		{
			if(d[m][p.ff] > d[m][a] + p.ss)
			{
				x.erase(mp(d[m][p.ff], p.ff));
				d[m][p.ff] = d[m][a] + p.ss;
				x.insert(mp(d[m][p.ff], p.ff));
			}
		}
	}
}

inline void SuperDijstra(int s)
{
	int m = (s == S ? 0 : 1);
	set<pair<ii,ll>> x;
	F0Re(i, N)
		dis[m][i] = mp(INF, INF);
	dis[m][s] = mp(0, d[m][s]);
	x.insert(mp(dis[m][s], s));
	while(!x.empty())
	{
		int a = (*x.begin()).ss;
		x.erase(x.begin());
		for(ii p : g[a])
		{
			if(dis[m][p.ff] > mp(dis[m][a].ff + p.ss, min(d[m][p.ff],dis[m][a].ss)))
			{
				x.erase(mp(dis[m][p.ff], p.ff));
				dis[m][p.ff] = mp(dis[m][a].ff + p.ss, min(d[m][p.ff],dis[m][a].ss));
				x.insert(mp(dis[m][p.ff], p.ff));
			}
		}
	}	
}

inline void solve()
{
	ii tmp = mp(INF, INF);
	F0Re(i, N)
		tmp = min(tmp, mp(dis[0][i].ff + dis[1][i].ff, dis[0][i].ss + dis[1][i].ss));
	ans = min(ans, min(tmp.ss, d[0][V]));
}

int main()
{
	
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	
	ll i, j, k;
	ans = INF;
	cin>>N>>M>>S>>T>>U>>V;
	while(M--)
	{
		cin>>i>>j>>k;
		g[i].pb(mp(j,k));
		g[j].pb(mp(i,k));
	}
	Dijkstra(U);
	Dijkstra(V);
	SuperDijstra(S);
	SuperDijstra(T);
	solve();
	swap(U, V);
	Dijkstra(U);
	Dijkstra(V);
	SuperDijstra(S);
	SuperDijstra(T);
	solve();
	cout<<ans;

	return 0;
}

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