QAQ

char dp[N][N]

for(int i=h[now];i;i=a[i].next)
{
    int y=a[i].to; 
    ...
        if(b[i]||spfa(y)) return 1;
}

f=read();
if(f=='1') x=read(),y=read(),z=read(),build(x,y,z);

struct node{int num,dis;}
queue<node> q;
...
q.push(dis[v],v);