poj3013Big Chrismas Tree——树转换spfa

#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
using namespace std;
typedef long long ll;
queue<int>q;
int t,n,m,head[50005],ct,s[50005];
bool in[50005];
ll dis[50005],INF=1e10,ans;
struct N{
    int to,next,w;
    N(int t=0,int n=0,int ww=0):to(t),next(n),w(ww) {}
}edge[100005];
int main()
{
    scanf("%d",&t);
    while(t--)
    {
        ct=0;
        memset(head,0,sizeof head);
        memset(in,0,sizeof in);
        scanf("%d%d",&n,&m);
        for(int i=1;i<=n;i++)
            scanf("%d",&s[i]),dis[i]=INF;
        for(int i=1;i<=m;i++)
        {
            int x,y,z;
            scanf("%d%d%d",&x,&y,&z);
            edge[++ct]=N(y,head[x],z);head[x]=ct;
            edge[++ct]=N(x,head[y],z);head[y]=ct;
        }
        while(q.size())q.pop();
        dis[1]=0;q.push(1);in[1]=1;
        while(q.size())
        {
            int x=q.front();q.pop();
            in[x]=0;
            for(int i=head[x];i;i=edge[i].next)
            {
                int u=edge[i].to;
                if(dis[u]>dis[x]+edge[i].w)
                {
                    dis[u]=dis[x]+edge[i].w;
                    if(!in[u])in[u]=1,q.push(u);
                }
            }
        }
        bool flag=0;ans=0;
        for(int i=1;i<=n;i++)
        {
            if(dis[i]==INF)
            {
                flag=1;break;
            }
            ans+=dis[i]*s[i];
        }
        if(flag)printf("No Answer\n");
        else printf("%lld\n",ans);
    }
    return 0;
}