洛谷单元最短路标准版——spfa优化

#include<cstdio>

#include<queue>

#include<vector>

#include<cstring>

using namespace std;

int n,m,k;

int dis[100001];

vector<int>a[100001],zhi[100001];

bool fin[100001];

struct pp

{

         int dian;

}dian;

priority_queue <pp>q;

bool operator <(pp a,pp b)

{

         return dis[a.dian]>dis[b.dian];

}

void shengcheng()

{

         for(int i=1;i<=n;i++)

         {

                   dis[i]=1000000009;

         }

         dis[k]=0;

         fin[k]=1;

         while(q.empty()==0)

         {

                   int u=q.top().dian;q.pop();

                   fin[u]=0;

                   for(int i=0;i<a[u].size();i++)

                   {

                            int w=a[u][i];

                            if(dis[w]>dis[u]+zhi[u][i])

                            {

                                     dis[w]=dis[u]+zhi[u][i];

                                     if(fin[w]==0)

                                     {

                                               fin[w]=1;

                                               dian.dian=w;

                                               q.push(dian);

                                     }

                            }

                   }

         }

}

int x,y,z;

int main()

{

         scanf("%d%d%d",&n,&m,&k);

         for(int i=1;i<=m;i++)

         {

                  

                   scanf("%d%d%d",&x,&y,&z);

                   a[x].push_back(y);

                   zhi[x].push_back(z);

                  

         }

         dian.dian=k;

         q.push(dian);

         shengcheng();

         for(int i=1;i<=n;i++)

         {

                   if(i!=k)

                   printf("%d ",dis[i]);

                   else

                   printf("0 ");

         }

         return 0;

}

我不会迪杰斯特拉，于是想出了这个来偷懒