1122 蓝桥王国

稀疏图：点多边少
稠密图：点少边多

#include<bits/stdc++.h>
using namespace std;
using ll =long long;
const ll N=3E5+9,inf=2e18;
ll d[N];
int n,m;

struct Node
{
  ll x,w;
  bool operator < (const Node &y) const
  {
     return w==y.w ? x< y.x : w>y.w;
  }
};
vector<Node>g[N];//存贮图

void dijkstra(ll st)//参数表示源点
{
   for(int i=1;i<=n;i++)d[i]=inf;
   bitset<N>vis;
   priority_queue<Node> pq;
   pq.push({st,d[st]=0});
   while(pq.size())
   {
     auto[x,w]=pq.top();pq.pop();
     if(vis[x])continue;
     vis[x]=true;
     for(const auto & [y,dw]:g[x])
     {
       if(d[x]+dw<d[y])
       {
         d[y]=d[x]+dw;
         pq.push({y,d[y]});
       }
     }
   }
}

int main()
{
   ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
   cin>>n>>m;
   while(m--)
   {
      ll u,v,w;cin>>u>>v>>w;
      g[u].push_back({v,w});
   }
   dijkstra(1);
   for(int i=1;i<=n;i++)
   {
     cout<<(d[i]>=inf ? -1 : d[i])<<" ";
   }
   return 0;
}