Submission #1274465

#	Time	Username	Problem	Language	Result	Execution time	Memory
1274465		KluydQ	Commuter Pass (JOI18_commuter_pass)	C++20	100 / 100	471 ms	22168 KiB

commuter_pass

#include <bits/stdc++.h>

#define respagold ios_base::sync_with_stdio(0), cin.tie(0);
#define int long long
#define ll long long
#define int2 __int128_t
#define FOR( i, x, n, d ) for( int i = x; i <= n; i += d )
#define FORR( i, x, n, d ) for( int i = x; i >= n; i -= d )
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x.size())
#define pb push_back
#define ins insert
#define lb lower_bound
#define ub upper_bound
#define pii pair <int, int>
#define ppi pair <pair <int, int>, int>
#define pip pair <int, pair <int, int>>
#define mkp make_pair

using namespace std;
 
const int N = 1e5 + 12;
const int mod = 1e9 + 7;
const int inf = 1e18;

int n, m, ans, V, U, S, T, d1[N][2], d2[N][2], d[N];
vector <pii> g[N]; set <pii> st;

void djk1( int start, int tp )
{
	FOR( i, 1, n, 1 ) d1[i][tp] = inf;
	d1[start][tp] = 0, st.ins({0, start});
	
	while( !st.empty() )
	{
		pii pp = *st.begin();
		int v = pp.S; st.erase(pp);
		
		for( auto i : g[v] )
		{
			int to = i.F, cost = i.S;
			
			if( d1[v][tp] + cost < d1[to][tp] )
			{
				st.erase({ d1[to][tp], to });
				d1[to][tp] = d1[v][tp] + cost;
				st.ins({ d1[to][tp], to });
			}
		}
	}
}
void djk2( int start )
{
	FOR( i, 1, n, 1 ) d2[i][0] = d2[i][1] = d[i] = inf;
	d2[start][0] = d1[start][0], d2[start][1] = d1[start][1];
	d[start] = 0, st.ins({0, start});
	
	while( !st.empty() )
	{
		pii pp = *st.begin();
		int v = pp.S; st.erase(pp);
		
		for( auto i : g[v] )
		{
			int to = i.F, cost = i.S;
			
			if( d[v] + cost < d[to] )
			{
				st.erase({ d[to], to });
				d[to] = d[v] + cost;
				st.ins({ d[to], to });
				
				d2[to][0] = min(d1[to][0], d2[v][0]);
				d2[to][1] = min(d1[to][1], d2[v][1]);
			}
			else if( d[v] + cost == d[to] && min(d2[v][0], d1[to][0]) + min(d2[v][1], d1[to][1]) < d2[to][0] + d2[to][1] )
			{
				d2[to][0] = min(d2[v][0], d1[to][0]);
				d2[to][1] = min(d2[v][1], d1[to][1]);
			}
		}
	}
}
void solve()
{
	cin >> n >> m >> S >> T >> U >> V;
	
	FOR( i, 1, m, 1 )
	{
		int x, y, z;
		cin >> x >> y >> z;
		
		g[x].pb({ y, z });
		g[y].pb({ x, z });
	}
	djk1(U, 0), djk1(V, 1);
	ans = min(d1[V][0], d1[U][1]);
	
	djk2(S); ans = min(ans, d2[T][0] + d2[T][1]);
	djk2(T); ans = min(ans, d2[S][0] + d2[S][1]);
	
	cout << ans << '\n';
}
signed main()
{
	respagold;
	
	int test = 1;
	if( !test ) cin >> test;
	while( test -- ) solve();
}

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