邻接表Dijkstra（求最短路径）

板子板子，学长给的

#include
using namespace std;
const int N=1100;
const int inf=0x3f3f3f3f;
bool vis[N];
int dis[N];
int n;
vector >mp[N];
struct node
{
    int id;//点
    int len;//边权
    friend bool operator <( node A,node B)
    {
        return A.len>B.len;
    }
};
void Dijkstra(int s)
{
    memset(dis,inf,sizeof(dis));
    memset(vis,false,sizeof(vis));
    dis[s]=0;
    priority_queueQ;
    Q.push(node{s,0});
    while(!Q.empty())
    {
        node u=Q.top();
        Q.pop();
        int xx=u.id;
        if(vis[xx])
            continue;
        vis[xx]=true;
        for(int i=0; idis[xx]+mp[xx][i].second)
            {
                dis[to]=dis[xx]+mp[xx][i].second;
                Q.push(node{to,dis[to]});
            }
        }
    }
}
int main()
{
    int n,m;

    cin>>n>>m;
    for(int i=0; i>a>>b>>c;
        mp[a].push_back(make_pair(b,c));
        mp[b].push_back(make_pair(a,c));
    }
    Dijkstra(1);
    for(int i=1; i<=n; i++)
        cout<<"S到序号"<

据说下面这个功能优化一点

#include
#include
#include
#include
#include
#include

#include
using namespace std;
const int N=1e3+100;
typedef long long ll;


struct node
{
    long long u,w;
    node(long long _u=0,long long _w=0):u(_u),w(_w){};
    bool operator <(const node &a) const
    {
        return w>a.w;
    }
};
struct Edge
{
    ll to,w,nextt;
}A[1010000];
ll head[N],vis[N],dis[N];
ll tot;
priority_queueq;
void addedge(ll from,ll to,ll w)
{
    A[tot].to=to;
    A[tot].w=w;
    A[tot].nextt=head[from];
    head[from]=tot++;
}
void Dijkstra(ll start)
{
    memset(dis,0x3f,sizeof(dis));
    memset(vis,0,sizeof(vis));
    dis[start]=0;
    while(!q.empty()) q.pop();
    q.push(node(start,0));
    node tem;
    while(!q.empty())
    {
        tem=q.top();
        q.pop();
        long long u=tem.u;
        if(vis[u]) continue;
        vis[u]=1;
        for(long long i=head[u];i!=-1;i=A[i].nextt)
        {
            long long v=A[i].to;
            long long w=A[i].w;
            if(!vis[v]&&dis[v]>dis[u]+w)
            {
                dis[v]=dis[u]+w;
                q.push(node(v,dis[v]));
            }
        }
    }
}
void init()
{
	memset(head,-1,sizeof(head));
      tot=0;
}
ll sovle1(int n)
{
	 Dijkstra(0);
     ll cc=0;
     for(long long i=1;i<=n;i++) cc=max(cc,dis[i]);
     return cc;
}
ll solve2(int s,int n)
{
	Dijkstra(s);
    ll cc=0;
    for(long long i=1;i<=n;i++) cc=max(cc,dis[i]);
   	return cc;
}
int main()
{
    
    int T;scanf("%d",&T);
    while(T--){
        init();
        ll n,m,s,k,c,t,u,v,w,x;
        scanf("%lld%lld%lld%lld%lld",&n,&m,&s,&k,&c);
        for(long long i=1;i<=k;i++){
            scanf("%lld",&x);
            addedge(0,x,0);
        }
        for(long long i=1;i<=m;i++)
        {
            scanf("%lld%lld%lld",&u,&v,&w);
            addedge(u,v,w);
            addedge(v,u,w);
        }
       
        ll t1=sovle1(n);
        ll t2=solve2(s,n);
        
        printf("%lld\n",t1*c>=t2?t2:t1);
    }
}