改进SPFA

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <string>
#include <vector>
#include <queue>
using namespace std;
#define inf 0x3f3f3f3f
struct A
{
    int ed;
    int power;
};
vector <A> v[1000100];
int dis[1000100],vis[1000100];
int path[10000];
int n,m;
queue<int> q;
void SPFA(int s,int n)
{
    memset(dis,inf,sizeof(dis));
    memset(vis,0,sizeof(vis));
    dis[s]=0;vis[s]=1;
    q.push(s);
    while(!q.empty())
    {
        int u=q.front();
        q.pop();vis[u]=0;
        for(int i=0;i<v[u].size();i++)
        {
            int x=v[u][i].ed;
            int y=v[u][i].power;
            if(dis[u]+y<dis[x])
            {
                dis[x]=dis[u]+y;
                path[x]=u;
                if(vis[x]==0)
                {
                    q.push(x);
                    vis[x]=1;
                }
            }
        }
    }
    return;
}
int main()
{
    cin>>n>>m;
    int i,j,k;
    for(i=0;i<m;i++)
    {
        int x,y,c;
        cin>>x>>y>>c;
        A t;
        t.ed=y;t.power=c;
        v[x].push_back(t);
        //t.ed=x;t.power=c;
        //v[y].push_back(t);
    }
    SPFA(0,n);
    for(i=1;i<n;i++)
        cout<<dis[i]<<" ";
    cout<<endl;
    for(i=1;i<n;i++)
        cout<<path[i]<<" ";
    return 0;
}