P3408: [Usaco2009 oct]heat wave heat wave

Water problem, bare shortest.

Constmaxn=6200001; type link=^node; Node=record t,d:longint;  F:link; End;varn,m,s,i,j,u,v,w,max:longint;adj:array[0.. the] of link;f:array[0..1000000] of longint;d,val:array[0.. the] of longint;went:array[0.. the] of boolean;procedure Insert (f,t,d:longint);varP:link;beginNew(P); P^.f:=Adj[f]; P^.t:=T; P^.d:=D; ADJ[F]:=p;end;procedure SPFA (s:longint);varL,r,now,i:longint;p:link;begin fori:=1to n DoD[i]:=MAXN; Fillchar (went,sizeof(went),true); L:=1; r:=1; f[1]:=s; d[s]:=0; went[s]:=false;  whileL<=r Dobegin now:=F[l]; P:=Adj[now];  whileP<>nil Dobeginifd[p^.t]>d[now]+p^. D THEN BEGIN d[p^.t]:=d[now]+p^. D; ifwent[p^. t] then begin WENT[P^.t]:=false;                  Inc (R); F[R]:=p^. T;            End          End P:=p^. F;      End Went[now]:=true;    Inc (L);  End;end;begin readln (n,m,s);  fori:=1to M Dobegin READLN (U,V,W);      Insert (U,V,W); //Insert (v,u,w);end;  fori:=1to n Do    ifI<>s THEN begin SPFA (i); Val[i]:=D[s];  End  SPFA (s);  fori:=1to n Do    ifI<>S THEN BEGIN Inc (Val[i],d[i]); ifVal[i]>max then max:=Val[i];  End Writeln (max); end.

P3408: [Usaco2009 oct]heat wave heat wave