Submission #2861344

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Source Code Expand

#include "bits/stdc++.h"
#define in std::cin
#define out std::cout
#define rep(i,N) for(int i=0;i<N;++i)
typedef long long int LL;
typedef std::pair<LL, LL> P;
struct edge { LL to, cost; };
 
const LL inf = 11234567890123;
LL N, M;
std::map<LL, LL>dist;
std::map<LL, std::vector<edge>>G;
 
void dijkstra(LL s)
{
	std::priority_queue<P, std::vector<P>, std::greater<P>>que;
	for (auto i : G) dist[i.first] = inf;
	dist[s] = 0;
	que.push(P(0, s));
	while (!que.empty())
	{
		P p = que.top(); que.pop();
		LL v = p.second;
		if (dist[v] < p.first) { continue; }
		rep(i, G[v].size())
		{
			edge e = G[v][i];
			if (dist[e.to] > dist[v] + e.cost)
			{
				dist[e.to] = dist[v] + e.cost;
				que.push(P(dist[e.to], e.to));
			}
		}
	}
}
 
int main()
{
	in >> N >> M;
	std::vector<LL>p(M), q(M), c(M);
	rep(i, M)
	{
		in >> p[i] >> q[i] >> c[i];
		G[p[i] + c[i] * N].push_back({ q[i] + c[i] * N,0 });
		G[q[i] + c[i] * N].push_back({ p[i] + c[i] * N,0 });
		G[p[i]].push_back({ p[i] + c[i] * N ,1 });
		G[p[i] + c[i] * N].push_back({ p[i] ,0 });
		G[q[i]].push_back({ q[i] + c[i] * N ,1 });
		G[q[i] + c[i] * N].push_back({ q[i] ,0 });
	}
	dist[N] = inf;
	dijkstra(1);
	out << (dist[N] >= inf ? -1 : dist[N]) << std::endl;
	return 0;
}

Submission Info

Judge Result