不是数组范围的问题，在自己电脑上狠狠的跑了11.29秒才出答案

#include<bits/stdc++.h>
using namespace std;
#define rint register int
const int maxn=1e5+5,inf=1e9;
struct edge{
	int to,nxt,w;
}e[maxn<<1];
struct node{
	int id,dis;
	friend bool operator<(node x,node y){return x.dis<y.dis;}
};
inline int read(){
	int f=1,x=0;
	char c=getchar();
	while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}
	while(c>='0'&&c<='9'){x=(x<<3)+(x<<1)+(c^'0');c=getchar();}
	return x*f;
}
int n,r;
int head[maxn],cntedge,dis1[maxn],dis2[maxn];
bool vis[maxn];
priority_queue<node>q;
inline void add_edge(int u,int v,int w){
	e[++cntedge]=edge{v,head[u],w};head[u]=cntedge;
}
inline void dij(int st){
	q.push(node{st,0});
	for(rint i=1;i<=n;i++)dis1[i]=dis2[i]=inf;
	dis1[st]=0;
	while(!q.empty()){
		int u=q.top().id,val=q.top().dis;
		q.pop();
		if(val>dis2[u])continue;
		for(rint i=head[u];i;i=e[i].nxt){
			int v=e[i].to,w=e[i].w;
			bool flag=0;
			if(dis1[v]>val+w){
				dis2[v]=dis1[v];
				dis1[v]=val+w;
				flag=1;
			}
			if(dis2[v]>val+w&&dis1[v]<val+w){
				dis2[v]=val+w;
				flag=1;
			}
			if(dis2[v]>dis2[u]+w){
				dis2[v]=dis2[u]+w;
			}
			if(flag)q.push(node{v,dis1[v]});
		}
	}
}
int main(){
//	freopen("1.in","r",stdin);
//	freopen("1.out","w",stdout); 
	n=read(),r=read();
	for(rint i=1;i<=r;i++){
		int u=read(),v=read(),w=read();
		add_edge(u,v,w),add_edge(v,u,w);
	}
	dij(1);
	printf("%d",dis2[n]);
	return 0;
}