Submission #719842

#	Time	Username	Problem	Language	Result	Execution time	Memory
719842		Juan	Commuter Pass (JOI18_commuter_pass)	C++14	0 / 100	459 ms	28084 KiB

commuter_pass

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define tii tuple<int, int, int>
#define pii pair<int, int>
#define ff first
#define ss second
const int maxn = 1e5 + 5, INF = 0x3f3f3f3f3f3f3f3f;

vector<pii> adj[maxn];
vector<int> g[maxn];
vector<tii> edges;
int n;

vector<int> dijkstra(int ini){
	priority_queue<pii, vector<pii>, greater<pii>> pq;
	vector<int> dist(n+1, INF);
	dist[ini] = 0;
	pq.push({0, ini});

	while(pq.size()){
		auto[d, u] = pq.top();
		pq.pop();
		if(d > dist[u]) continue;

		for(int v : g[u]) if(dist[u] < dist[v]){
			dist[v] = dist[u];
			pq.push({dist[u], v});
		}

		for(auto [v, w] : adj[u]) if(dist[u]+w < dist[v]){
			dist[v] = dist[u] + w;
			pq.push({dist[u]+w, v});
		}
	}

	return dist;
}

int32_t main(){
	int m; cin >> n >> m;
	int S, T; cin >> S >> T;
	int U, V; cin >> U >> V;
	for(int i = 0; i < m; i++){
		int a, b, c; cin >> a >> b >> c;
		adj[a].push_back({b, c});
		adj[b].push_back({a, c});
		edges.push_back({a, b, c});
	}

	vector<int> distS = dijkstra(S), distT = dijkstra(T);
	int minpath = distS[T];

	for(auto[a, b, c] : edges) if(distS[a] < distS[b]){
		if(distS[a]+c+distT[b] == minpath) g[a].push_back(b);
	}
	vector<int> dist1 = dijkstra(U);
	int ans = dist1[V];

	for(int i = 1; i <= n; i++) g[i].clear();
	for(auto[a, b, c] : edges) if(distS[a] < distS[b]){
		if(distS[a]+c+distT[b] == minpath) g[b].push_back(a);
	}
	vector<int> dist2 = dijkstra(U);
	ans = min(ans, dist2[V]);

	cout << ans << '\n';
}

Compilation message (stderr)

commuter_pass.cpp: In function 'std::vector<long long int> dijkstra(long long int)':
commuter_pass.cpp:22:7: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   22 |   auto[d, u] = pq.top();
      |       ^
commuter_pass.cpp:31:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   31 |   for(auto [v, w] : adj[u]) if(dist[u]+w < dist[v]){
      |            ^
commuter_pass.cpp: In function 'int32_t main()':
commuter_pass.cpp:54:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   54 |  for(auto[a, b, c] : edges) if(distS[a] < distS[b]){
      |          ^
commuter_pass.cpp:61:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   61 |  for(auto[a, b, c] : edges) if(distS[a] < distS[b]){
      |          ^

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