The dijkstral algorithm of Usaco--3.2sweet butter+ push optimization

The idea of this topic is very simple, we just need to enumerate each vertex as the destination, and then take the sum of the minimum distance as the answer. At first I used Floyd to find out the minimum distance between all points at once, but it timed out.
The next time you enumerate a point, use the heap-optimized dijkstral to find the shortest path to the rest of the point, so it's too late. The adjacency matrix of the graph is also simulated with an array in the algorithm.

The code is as follows:

/*id:15674811lang:c++task:butter*/#include <iostream>#include <cstdio>#include <cstring>#include <queue>using namespace STD;#define MAXN 810#define INF 0x3f3f3f3fintP[MAXN],D[MAXN],FIRST[MAXN],VIS[MAXN];intu[maxn*Ten],v[maxn*Ten],w[maxn*Ten],next[maxn*Ten];intE,n,k,m;;voidAdd_e (intXintYintz) {u[e]=x; v[e]=y; w[e]=z;       NEXT[E]=FIRST[X]; first[x]=e++;}typedefpair<int,int&GT;PII;PRIORITY_QUEUE&LT;PII, vector<pii>,greater<pii> >q;voidDijkstral (intx) {memset(Vis,0,sizeof(VIS));memset(d,0x3f,sizeof(d)); d[x]=0; Q.push (Make_pair (d[x],x)); while(!q.empty ()) {PII u=q.top (); Q.pop ();intX=u.second;if(Vis[x])Continue; vis[x]=1; for(intk=first[x];k!=-1; K=next[k])if(D[v[k]]>d[x]+w[k])                      {D[v[k]]=d[x]+w[k];                 Q.push (Make_pair (d[v[k]],v[k)); }      }}intMain () {Freopen ("Butter.in","R", stdin); Freopen ("Butter.out","W", stdout);//freopen ("In.txt", "R", stdin);       intSum=inf;scanf("%d%d%d", &k,&n,&m); for(intI=0; i<k;i++)scanf("%d", &p[i]); E=0; for(intI=1; i<=n;i++) first[i]=-1; for(intI=1; i<=m;i++) {intX, Y, Zscanf("%d%d%d", &x,&y,&z);             Add_e (x, y, z);      Add_e (Y,X,Z); } for(intI=1; i<=n;i++) {dijkstral (i);inttmp=0, J; for(j=0; j<k;j++) {if(D[p[j]]>=inf) Break;            TMP+=D[P[J]]; }if(j>=k&&sum>tmp) sum=tmp; }printf("%d\n", sum);return 0;}

The dijkstral algorithm of Usaco--3.2sweet butter+ push optimization