1. 用STL的优先队列

#include <iostream>
#include <queue>
#include <vector>
using namespace std;
const int N=405;
struct rec
{
    int v,w;
};
vector<rec> edge[N*N];
int n,st,ed;
__int64 dis[N*N];
bool vis[N*N];
struct cmp
{
    bool operator()(int a,int b)
    { 
        return dis[a]>dis[b];
    } 
};
void Dijkstra()
{
    priority_queue<int,vector<int>,cmp> Q;
    memset(dis,-1,sizeof(dis));
    memset(vis,0,sizeof(vis));
    int i,u,v;
    Q.push(st);
    dis[st]=0;
    while(!Q.empty())
    {
        u=Q.top();
        Q.pop();
        vis[u]=0;
        if(u==ed)
            break;
        for(i=0;i<edge[u].size();i++)
        {
            v=edge[u][i].v;
            if(dis[v]==-1 || dis[v]>dis[u]+edge[u][i].w)
            {
                dis[v]=dis[u]+edge[u][i].w;
                if(!vis[v])
                {
                    vis[v]=1;
                    Q.push(v);
                }
            }
        }
    }
}

2.手动写堆

#include <iostream>
#include <queue>
#include <vector>
using namespace std;
const int N=405;
struct rec
{
    int v,w;
};
vector<rec> edge[N*N];
int n,st,ed;
__int64 dis[N*N];
bool inHeap[N*N];
int heap[N*N];//存储节点id的堆
int inhp[N*N];//存储节点id在堆里面的位置
int size;//堆的大小
void upData(int x)
{
	while(x>1)
	{
        int px=x>>1;
		if(dis[heap[x]]<dis[heap[px]])
		{
			int temp;
                
            inhp[heap[x]]=px;
            inhp[heap[px]]=x;
                
            temp=heap[x];
            heap[x]=heap[px];
            heap[px]=temp;
                    
            x=px;
		}
        else
            break;
	}
}
void downData(int x)
{
	int lx,rx;
    while(x<=size/2)
	{
		lx=x<<1;
        rx=lx+1;
        int sx=x;
		if(lx<=size &&dis[heap[sx]]>dis[heap[lx]])
        {
            sx=lx;
		}
        if(rx<=size &&dis[heap[sx]]>dis[heap[rx]])
		{
            sx=rx;
		}
        if(sx==x)
            break;
		inhp[heap[x]]=sx;
        inhp[heap[sx]]=x;
            
        int temp=heap[x];
		heap[x]=heap[sx];
        heap[sx]=temp;
        x=sx;
	}
}
void Dijkstra()
{
	memset(dis,-1,sizeof(dis));
    memset(inHeap,0,sizeof(inHeap));
    size=1;
    heap[1]=st;
    inhp[st]=1;
    int i,u,v;
	dis[st]=0;
    while(size>0)
    {
		u=heap[1];
        if(u==ed)
        {
            break;
        }
        int temp;
        temp=heap[1];
        heap[1]=heap[size];
        heap[size]=temp;
		inhp[heap[1]]=1;
        size--;
        downData(1);
        inHeap[u]=false;
        for(i=0;i<edge[u].size();i++)
        {
            v=edge[u][i].v;
            if(dis[v]==-1 || dis[v]>dis[u]+edge[u][i].w)
            {
                dis[v]=dis[u]+edge[u][i].w;
                if(!inHeap[v])
                {
                    inHeap[v]=true;
                    size++;
                    heap[size]=v;
                    inhp[v]=size;
                    upData(size);
                }
                else
                {
                    upData(inhp[v]);
                }
            }
        }
    }
        
}