제출 #1021220

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1021220		EkinOnal	Commuter Pass (JOI18_commuter_pass)	C++17	31 / 100	294 ms	22544 KiB

commuter_pass

//#pragma GCC optimize("O3,unroll-loops,Ofast")
//#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")
#include <bits/stdc++.h>
//#include <cstdio>
//#include <iostream>
using namespace std;
 
#define MAX 100007
#define pb push_back
//#define mp make_pair 
#define int long long
#define f first
#define s second
#define vi vector<int>
#define pii pair<int,int>
#define si set<int>
#define vpii vector<pair<int,int>> 
const int mod = 1e9+7;
const int INF = 1e18;
// myMap.begin()->first :  key
// myMap.begin()->second : value
 
int epow(int a,int b){int ans=1;while(b){if(b&1) ans*=a;a*=a;ans%=mod;a%=mod;b>>=1;}return ans%mod;}
int gcd(int a,int b) {if(a<b)swap(a,b);while(b){int tmp=b;b=a%b;a=tmp;}return a;}
int mul(int a,int b){return ((a%mod)*(b%mod))%mod;}
 
 
int dx[] = {-1, 0, 1, 0};
int dy[] = {0, -1, 0, 1};
 
#define N 50
 
vector<pii> adj[MAX];
int n,m,s,t,u,v;
void dijkstra(vi &dist,int start,int finish)
{
	priority_queue<pii,vector<pii>,greater<pii>> pq;
	pq.push({0,start});  dist[start]=0;
	while(pq.size())
	{
		int node = pq.top().s, cost=pq.top().f;
		pq.pop();
		if(cost != dist[node]) continue;
		for(auto u : adj[node])
		{
			int nxt = u.f, len=u.s;
			if(dist[nxt] > cost+len)
			{
				dist[nxt] = cost+len;
				pq.push({dist[nxt],nxt});
			}
		}
	}
}

 
 
void solve() 
{	
 	cin >> n >> m;
 	cin >> s >> t;
 	cin >> u >> v;

 	for(int i=0;i<m;i++)
 	{
 		int a,b,c; cin>>a>>b>>c;
 		adj[a].pb({b,c}); adj[b].pb({a,c});
 	}

 	vi dist(n+2,INF),dist1(n+2,INF),dist2(n+2,INF);
 	dijkstra(dist,s,t);
 	int mn = dist[t];
 	dijkstra(dist2,t,s);



 	priority_queue<pii,vector<pii>,greater<pii>> pq;
	pq.push({0,u});  dist1[u]=0;
	while(pq.size())
	{
		int node = pq.top().s, cost=pq.top().f;
		pq.pop();
		if(cost != dist1[node]) continue;
		for(auto u : adj[node])
		{
			int nxt = u.f, len=u.s;
			if(dist[node]+dist2[nxt]+len==mn || dist[nxt]+dist2[node]+len==mn 
			  /*dist[nxt]==dist[node]+len || dist[node]==dist[nxt]+len*/)
			{
				if(dist1[nxt] > dist1[node])
				{
					dist1[nxt]=dist1[node];
					pq.push({dist1[nxt],nxt});
				}
			}
			else if(dist1[nxt] > cost+len)
			{
				dist1[nxt] = cost+len;
				pq.push({dist1[nxt],nxt});
			} 
		}
	}
	cout << dist1[v] << endl;
//	for(int i=1;i<=n;i++) cout << dist[i] << " ";cout<<endl;
//	for(int i=1;i<=n;i++) cout << dist1[i] << " ";cout<<endl;
	
    return;
}	
 
 
 
int32_t main()
{
	int t=1;
//	cin >> t;
	while(t--) solve();

	return 0;
}

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