求助啊，WA了。。

花了好久了，求助啊

#include<bits/stdc++.h>
using namespace std;
int n,m,ans,cnt;
int d[100010];
int edge[100010],son[100010];
int c[100010];
bool b[100010];
bool jud;
queue<int>q;
vector<int>v[100010];
vector<int>e[100010];
bool read(int& x)
{
    char c=getchar();
    x=0;
    while(c<'0'||c>'9')
    {
        if(c==EOF)return 0;
        c=getchar();
    }
    while(c>='0'&&c<='9')
    {
        x=x*10+c-'0';
        c=getchar();
    }
    return 1;
}
void bfs(int s)
{
    d[s]=0;
    q.push(s);
    b[s]=1;
    while(!q.empty())
    {
        int fa=q.front();
        q.pop();
//      cout<<fa<<endl;
        for(int i=0; i<v[fa].size(); i++)
        {
            int y=v[fa][i];
            if(b[y])continue;
            b[y]=1;
            d[y]=d[fa]+1;
            q.push(y);
        }
    }
}
void bfs2(int s)
{
    while(!q.empty())
    {
        int fa=q.front();
        q.pop();
        int minn=edge[fa];
        int nxt=son[fa];
        if(fa==n)return ;
        for(int i=0;i<v[fa].size();i++)
        {
            int y=v[fa][i];
            int z=e[fa][i];
            if(d[fa]-d[y]==1)
            {
                if(minn==z)
                {
                    if(edge[y]<edge[nxt])
                    {
                        nxt=y;
                    }
                }
            }
        }
        c[++cnt]=minn;
        q.push(nxt);
    }
}
int main()
{
    while(read(n)&&read(m))
    {
        ans=0;
        while(!q.empty())q.pop();
        for(int i=1;i<=n;i++)
        {
            v[i].clear();
            e[i].clear();
        }
        memset(b,0,sizeof(b));
        memset(d,0,sizeof(d));
        memset(edge,0x3f3f3f3f,sizeof(edge));
        memset(son,0,sizeof(son));
        for(int i=1; i<=m; i++)
        {
            int x,y,z;
            read(x);
            read(y);
            read(z);
            v[x].push_back(y);
            v[y].push_back(x);
            e[x].push_back(z);
            e[y].push_back(z);
        }
        bfs(n);
        printf("%d\n",d[1]);
        for(int i=1;i<=n;i++)
        {
            for(int j=0;j<v[i].size();j++)
            {
                int z=e[i][j];
                int y=v[i][j];
                if(edge[i]>z&&d[i]-d[y]==1)
                {
                    edge[i]=z;
                    son[i]=y;
                }
            }
        }
        q.push(1);
        bfs2(1);
        for(int i=1;i<=d[1];i++)
        {
            if(i!=d[1])
            printf("%d ",c[i]);
            else
            printf("%d",c[i]);
        }
        putchar('\n');
    }
}