模板 图论 Dijkstra+堆优化

#include <iostream>
#include <cstring>
#include <vector>
#include <queue>
#define INF 0xfffffff
#define MAXN 1000100
using namespace std;
struct node{
    int v;
    int c;
    node(int _v=0,int _c=0):v(_v),c(_c){}
    bool operator < (const node &r)const{
          return c>r.c;
          }
};
struct Edge{
    int v,cost;
    Edge(int _v=0,int _cost=0):v(_v),cost(_cost){}
};
vector <Edge> E[MAXN];
bool vis[MAXN];
int dist[MAXN];
void Dijkstra(int n,int start)
{
    memset(vis,0,sizeof(vis));
    for(int i=0;i<=n;i++)   dist[i]=INF;
    priority_queue <node> que;
    while(!que.empty()) que.pop();
    dist[start]=0;
    que.push(node(start,0));
    node tmp;
    while(!que.empty())
    {
        tmp=que.top();
        que.pop();
        int u=tmp.v;
        if(vis[u])  continue;
        vis[u]=true;
        for(int i=0;i<E[u].size();i++)
        {
            int v=E[tmp.v][i].v;
            int cost=E[u][i].cost;
            if(!vis[v]&&dist[v]>dist[u]+cost)
            {
                dist[v]=dist[u]+cost;
                que.push(node(v,dist[v]));
            }
        }
    }
}
void addedge(int u,int v,int w)
{
    E[u].push_back(Edge(v,w));
}