最短路板子

#include <bits/stdc++.h>
#define ll long long
static const int INFTY=2147483647;
const int maxm=500010;
using namespace std;
struct edge{
    int t,w,next;
}e[maxm*2];
ll first[maxm*2],dis[maxm*2],ent;
bool vis[maxm*2];
int n,m,s;
void add(int u,int v,int w)
{
    e[++ent].t=v;e[ent].w=w;e[ent].next=first[u];first[u]=ent;
}
struct node{
    int dis,pos;
    bool operator<(const node &x)const
    {
        return x.dis<dis;
    }
};
std::priority_queue<node> q;
void dij()
{
    dis[s]=0;q.push((node){0,s});
    while(!q.empty())
    {
        node tem=q.top();q.pop();
        int x=tem.pos;
        if(vis[x])continue;
        vis[x]=1;
        for(int i=first[x];i;i=e[i].next)
        {
            int t=e[i].t;
            if(dis[t]>dis[x]+e[i].w)
            {
                dis[t]=dis[x]+e[i].w;
                if(!vis[t])
                q.push((node){dis[t],t});
            }
        }
    }
}
int main()
{
    scanf( "%d%d%d", &n, &m, &s );
    for(int i = 1; i <= n; ++i)
    dis[i] = INFTY;
    for(int i = 0; i < m; ++i )
    {
        int u, v, d;
        scanf( "%d%d%d", &u, &v, &d );
        add( u, v, d );
    }
    dij();
    for( int i = 1; i <= n; i++ )
        printf( "%d ", dis[i] );
    return 0;
}

#include<bits/stdc++.h>
#define ll long long
using namespace std;
struct data{
    int from;
    int to;
    int w;
    int next;
}a[500001];
queue<int> q;
bool vis[10001];
int first[10001];
ll d[10001];
int m,n,s,ent;
inline int read()
{
    char ch;
    int f=1,num=0;
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){num=num*10+ch-'0';ch=getchar();}
    return f*num;
}
inline void add(int u,int v,int ww)
{
    ent++;
    a[ent].from=u;
    a[ent].to=v;
    a[ent].w=ww;
    a[ent].next=first[u];
    first[u]=ent;
}
void spfa()
{
    q.push(s);
    d[s]=0;
    vis[s]=1;
    while(!q.empty())
    {
        int h=q.front() ;
        q.pop() ;
        vis[h]=0;
        for(int i=first[h];i;i=a[i].next )
        {
            int tt=a[i].to;
            if(d[h]+a[i].w<d[tt])
            {
                d[tt]=d[h]+a[i].w;
                if(!vis[tt])
                {
                    q.push(tt);
                    vis[tt]=true;
                }
            }
        }
    } 
}
int main()
{
    n=read();m=read();s=read();
    for(int i=1;i<=m;i++)
    {
        int u,v,p;
        u=read();v=read();p=read();
        add(u,v,p);
    }
    for(int i=1;i<=n;i++)
    d[i]=2147483647;
    spfa();
    for(int i=1;i<=n;i++)
    printf("%lld ",d[i]);
    return 0;
}