BZOJ 2100 Apple Delivery

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<deque>
#define maxv 100050
#define maxe 400050
#define inf 0x7f7f7f7f
using namespace std;
struct edge
{
int v,w,nxt;
}e[maxe];
int n,m,s,t1,t2,nume=0,g[maxv],dis[maxv],a,b,c,ans=inf;
bool vis[maxv];
deque <int> q;
void addedge(int u,int v,int w)
{
e[++nume].v=v;
e[nume].w=w;
e[nume].nxt=g[u];
g[u]=nume;
}
void spfa(int x)
{
while (!q.empty())    q.pop_front();
memset(vis,false,sizeof(vis));
fill(dis+1,dis+n+1,inf);
q.push_front(x);vis[x]=true;dis[x]=0;
while (!q.empty())
{
int head=q.front();q.pop_front();vis[head]=false;
for (int i=g[head];i;i=e[i].nxt)
{
int v=e[i].v;
if (dis[v]>dis[head]+e[i].w)
{
dis[v]=dis[head]+e[i].w;
if (!vis[v])
{
if (q.empty()) q.push_front(v);
else if (dis[v]<dis[q.front()]) q.push_front(v);
else q.push_back(v);
}
}
}
}
}
int main()
{
scanf("%d%d%d%d%d",&m,&n,&s,&t1,&t2);
for (int i=1;i<=m;i++)
{
scanf("%d%d%d",&a,&b,&c);
addedge(a,b,c);
addedge(b,a,c);
}
spfa(t1);
ans=dis[s]+dis[t2];
spfa(t2);
ans=min(ans,dis[s]+dis[t1]);
printf("%d\n",ans);
return 0;
}