@[wdzxghl](/user/266774) 你没有判断当前点是否访问过，看注释就知道了
```cpp
#include<bits/stdc++.h>
using namespace std;
const int maxn=2000010,inf=INT_MAX;
struct Edge {
long long to,next,w;
} edge[maxn];
Edge edge1[maxn];
long long dis[maxn],p[maxn],vis[maxn],edge_num,edge_num1,dis1[maxn],p1[maxn],vis1[maxn];
int n,m;
void add_edge(int u,int v,int w) {
edge[++edge_num].next=p[u];
edge[edge_num].to=v;
edge[edge_num].w=w;
p[u]=edge_num;
}
void add_edge1(long long u,long long v,long long w) {
edge1[++edge_num1].next=p1[u];
edge1[edge_num1].to=v;
edge1[edge_num1].w=w;
p1[u]=edge_num1;
}
void dijkstra() {
priority_queue<pair<long long,long long> >que;
//vis初始化为0即可
memset(vis,0,sizeof(vis));
for(long long i=1; i<=n; i++)
dis[i]=inf;
dis[1]=0;
//不必初始化vis[1]
//vis[1] = 0;
que.push(make_pair(0,1));
while(!que.empty()) {
int x=que.top().second;
que.pop();
//判断当前点是否访问过，如果访问过就可以略过
if(vis[x]) continue;
//将当前点设置为已访问
vis[x] = 1;
for(long long i=p[x]; i; i=edge[i].next) {
long long tmp=edge[i].to;
if(dis[tmp]>dis[x]+edge[i].w) {
dis[tmp]=dis[x]+edge[i].w;
que.push(make_pair(-dis[tmp],tmp));
}
}
}
}
void dijkstra1() {
priority_queue<pair<long long,long long> >que1;
//vis1初始化为0即可
memset(vis1,0,sizeof(vis1));
for(long long i=1; i<=n; i++)
dis1[i]=inf;
dis1[1]=0;
//不必初始化vis1[1]
//vis1[1] = 0;
que1.push(make_pair(0,1));
while(!que1.empty()) {
long long x=que1.top().second;
que1.pop();
//判断当前点是否访问过，如果访问过就可以略过
if(vis1[x]) continue;
//将当前点设置为已访问
vis1[x] = 1;
for(long long i=p1[x]; i; i=edge1[i].next) {
long long tmp=edge1[i].to;
if(dis1[tmp]>dis1[x]+edge1[i].w) {
dis1[tmp]=dis1[x]+edge1[i].w;
que1.push(make_pair(-dis1[tmp],tmp));
}
}
}
}
int main() {
cin>>n>>m;
memset(p,0,sizeof(p));
while(m--) {
long long u,v,w;
cin>>u>>v>>w;
add_edge(u,v,w);
add_edge1(v,u,w);
}
dijkstra();
dijkstra1();
long long cnt=0;
for(int i=1; i<=n; i++)
cnt+=dis[i]+dis1[i];
cout<<cnt<<endl;
return 0;
}
```
by Eloik @ 2020-10-12 21:36:47
@[Eloik](/user/261451) 谢谢dalao
by wdzxghl @ 2020-10-13 12:08:38