Submission #772763

#	Time	Username	Problem	Language	Result	Execution time	Memory
772763		ZeroCool	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	243 ms	25772 KiB

commuter_pass

#include <bits/stdc++.h>

#define int long long
#define debug(u) cerr<<(u == inf ? "inf" : to_string(u))<<endl
#define int long long


using namespace std;
using namespace chrono;


const int mxn = 100005;
const int inf = 1e18;

const int LOG = 17;

int n,m,s,t,u,v;
vector<pair<int,int> > g[mxn];



void dijk(int x, vector<int>&dis){
	priority_queue<pair<int,int> > pq;
	dis[x] = 0;
	pq.push({0,x});
	while(pq.size()){
		int x = (pq.top()).second;
		pq.pop();
		for(auto p : g[x]){
			if(dis[p.first] > dis[x] +p.second){
				dis[p.first] = dis[x] + p.second;
				pq.push({-dis[p.first],p.first});
			}
		}
	}
}

void solve(int T){
	cin >> n >> m >> s >> t >> u >> v;
	while(m--){
		int x, y, w;
		cin >> x >> y >> w;

		g[x].push_back({y, w});
		g[y].push_back({x, w});
	}
	vector<int> disu(n+1, 1e17), disv(n+1, 1e17), dis(n+1, 1e17), canu(n+1, 1e17), canv(n+1, 1e17);
	dijk(v, disv); dijk(u, disu);
	vector<bool> vis(n+1, 0);
	priority_queue<pair<pair<int,int>,int>, vector<pair<pair<int,int>,int>>, greater<pair<pair<int,int>,int>>> q;
	q.push({{0, s}, 0});
	dis[s] = 0;
	while(!q.empty()){
		int w = q.top().first.first;
		int x = q.top().first.second, pr = q.top().second;
		q.pop();
		if (w != dis[x]) continue;
		if (min(disv[x], canv[pr])+min(disu[x], canu[pr]) < canu[x]+canv[x]){
			canv[x] = min(disv[x], canv[pr]);
			canu[x] = min(disu[x], canu[pr]);
		}
		if (vis[x]) continue;
		vis[x] = 1;
		for (auto i : g[x]){
			if (dis[i.first] >= dis[x]+i.second){
				dis[i.first] = dis[x]+i.second;
				q.push({{dis[i.first], i.first}, x});
			}
		}
	}
	cout << min(canu[t]+canv[t], disv[u]);
}



int32_t main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	int t = 1;
	//cin>>t;
	for(int i = 1;i<=t;i++){
		solve(i);
		
	}
	
}

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