Coderforces 20C 最短路记录路径

#include<iostream>
#include<algorithm>
#include<string>
#include<cstring>
#include<map>
#include<queue>
#include<cmath>
#include<stack>
#include<vector>
#include<cstdio>
#define MAXN 33000
#define INF 0x3f3f3f3f
#define lmid l,m,rt<<1
#define rmid m+1,r,rt<<1|1
#define ls rt<<1
#define rs rt<<1|1
#define Mod 1000000007
#define i64 __int64
#define LIMIT_ULL 100000000000000000
using namespace std;
typedef pair<long long,int>P;
struct node
{
int v,w;
int next;
}s[200005];
int head[100005];
int cnt=1;
void add(int u,int v,int w)
{
s[cnt].v=v;
s[cnt].w=w;
s[cnt].next=head[u];
head[u]=cnt++;
}
long long dj[100005];
int lj[100005];
int jl[100005];
int n,m;
void djstl(int pos)
{
lj[pos]=pos;
fill(dj+1,dj+n+1,100000000000);
dj[pos]=0;
priority_queue<P,vector<P>,greater<P>>q;
q.push(P(0,pos));
node e;
while(!q.empty())
{
P p=q.top();
q.pop();
int v=p.second;
if(p.first>dj[v])
continue;
for(int i=head[v];~i;i=s[i].next)
{
e=s[i];
if(dj[e.v]>dj[v]+e.w)
{
lj[e.v]=v;
dj[e.v]=dj[v]+e.w;
q.push(P(dj[e.v],e.v));
}
}
}
}
int main()
{
scanf("%d%d",&n,&m);
memset(head,-1,sizeof(head));
for(int i=0;i<m;i++)
{
int a,b,c;
scanf("%d%d%d",&a,&b,&c);
add(a,b,c);
add(b,a,c);
}
djstl(1);
if(dj
==100000000000)
cout<<-1<<endl;
else
{
int len=0;
int k=n;
while(lj[k]!=1)
{
jl[len++]=lj[k];
k=lj[k];
}
jl[len++]=lj[k];
for(int i=len-1;i>=0;i--)
{
cout<<jl[i]<<" ";
}
cout<<n<<endl;
}
return 0;
}