#include #include #include #include using namespace std; typedef long long ll; typedef pair Pll; const int MAX_N = 112345; int n,m,a,b; ll c; vector d(MAX_N*2, 1LL << 60); priority_queue< Pll, vector, greater > que; vector< vector > edges(MAX_N*2); void dijkstra(ll start){ d[start] = 0; d[n+start] = 0; que.push(Pll(0, start)); while(!que.empty()){ Pll v = que.top(); que.pop(); if(d[v.second] < v.first) continue; for(Pll e: edges[v.second]){ if(d[e.first] > d[v.second] + e.second){ d[e.first] = d[v.second] + e.second; que.push(Pll(d[e.first], e.first)); } } } } int main() { cin >> n >> m; for(int i=0;i> a >> b >> c; --a; --b; edges[a].emplace_back(b, c); edges[b].emplace_back(a, c); edges[a].emplace_back(n+b, 0); edges[b].emplace_back(n+a, 0); edges[n+a].emplace_back(n+b, c); edges[n+b].emplace_back(n+a, c); } dijkstra(0); for(int i=0;i