WHY FK TLE

感觉算法和紫书上的没问题

#include <bits/stdc++.h>
using namespace std;
#define INF 0x3f3f3f3f3f
#define ll long long
#define int long long
#define MAXN 200019
#define none 1145141919810
#define WA puts("CCF")
int n,m;
vector<int> bq[MAXN];
vector<int> bqf[MAXN];//
vector<int> pq[MAXN];
vector<int> pqf[MAXN];//
int fl[MAXN];
deque<int> q;
deque<int> dep;
void bfs1()
{
    q.clear();
    dep.clear();
    q.push_back(1);
    dep.push_back(1);
    while(!q.empty())
    {
        int top=q.front();
        int dp=dep.front();
        dep.pop_front();
        q.pop_front();
        if(fl[top]>dp) fl[top]=dp;
        else continue;
        for(int i=0;i<pq[top].size();i++)
        {
            int g=pq[top][i];
            dep.push_back(dp+1);
            q.push_back(g);
        }
    }
    return ;
}
//vector<int> ans;
int qq[MAXN];//minn

void bfs2()
{
    q.clear();
    dep.clear();//前驱
    q.push_back(1);
    dep.push_back(-1);
    qq[0]=-1;
    //dep.push_back(1);
    while(!q.empty())
    {
        int top=q.front();
        //cout<<top<<"\n";
        int dp=dep.front();
        dep.pop_front();
        q.pop_front();
        if(dp!=qq[fl[top]-1]) continue;
        //WA;
        if(top==n) break;
        int minn=INF,mins;
        for(int i=0;i<pq[top].size();i++)
        {
            int g=pq[top][i];
            int val=bq[top][i];
            if(minn>val&&fl[top]+1==fl[g])
            {
                minn=val;
                mins=g;
            }
        }
        //q.push_back(mins);
        //ans.push_back(minn);
        for(int i=0;i<pq[top].size();i++)
        {
            int g=pq[top][i];
            int val=bq[top][i];
            if(fl[top]+1==fl[g]&&minn==val)
            {
                q.push_back(g);
                dep.push_back(val);
                //ans[fl[top]]=minn;
            }
        }
        //9cout<<top<<" "<<minn<<"\n";
        qq[fl[top]]=min(qq[fl[top]],minn);
    }
    return ;
}
 main()
{
    //cout<<INF;
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    while(cin>>n>>m)
    {
        for(int i=1;i<=n;i++) { qq[i]=INF; fl[i]=INF; bq[i].clear(); pq[i].clear(); /*bqf[i].clear(); pqf[i].clear();*/ }
        for(int i=1;i<=m;i++)
        {
            int u,v,w;
            cin>>u>>v>>w;
            pq[u].push_back(v);
            bq[u].push_back(w);
            pq[v].push_back(u);
            bq[v].push_back(w);
        }
        bfs1();
        cout<<(fl[n]-1)<<"\n";
        //for(int i=1;i<=n;i++) cout<<fl[i]<<" ";
        bfs2();
        for(int i=1;i<=fl[n]-1;i++) { cout<<qq[i]; if(fl[n]-1!=i) { cout<<" "; } }
        //while(!ans.empty()) { cout<<ans.back()<<" "; ans.pop_back(); }
        cout<<"\n";
    }
    return 0;
}
/*
6 6
6 5 1
5 4 4
4 1 2
1 2 2
2 3 2
3 6 3
*/