bzoj1001 spfa

const    maxn=2000009;  var    s,t,n,m,e:longint;    last,d,state:array[0..maxn] of longint;    side:array[1..maxn*3] of record      x,y,z,next:longint;    end;    v:array[0..maxn] of boolean;    flag:boolean;  procedure add(x,y,z:longint);  begin    inc(e);    side[e].x:=x; side[e].y:=y; side[e].z:=z;    side[e].next:=last[x]; last[x]:=e;    inc(e);    side[e].x:=y; side[e].y:=x; side[e].z:=z;    side[e].next:=last[y]; last[y]:=e;  end;  procedure init;  var    i,j,ans,x:longint;  begin    ans:=maxlongint;    readln(n,m);    flag:=true;    if (n=1)or(m=1) then flag:=false;    if (n=1)and(m=1) then    begin      writeln(0);      exit;    end;    if n=1 then    begin      for i:=1 to m-1 do      begin        read(x);        if x<ans then ans:=x;      end;      writeln(ans);      exit;    end;    if m=1 then    begin      for i:=1 to n-1 do      begin        read(x);        if x<ans then ans:=x;      end;      writeln(ans);      exit;    end;    s:=0;    t:=2*(n-1)*(m-1)+1;    for i:=1 to m-1 do    begin      read(x);      add(i*2,t,x);    end;    for i:=2 to n-1 do      for j:=1 to m-1 do      begin        read(x);        add(2*(i-1)*(m-1)+j*2,2*(i-2)*(m-1)+j*2-1,x);      end;    for i:=1 to m-1 do    begin      read(x);      add(s,2*(n-2)*(m-1)+i*2-1,x)    end;    for i:=1 to n-1 do    begin      read(x);      add(s,2*(i-1)*(m-1)+1,x);      for j:=2 to m-1 do      begin        read(x);        add(2*(i-1)*(m-1)+2*j-1,2*(i-1)*(m-1)+2*(j-1),x);      end;      read(x);      add(t,2*(i-1)*(m-1)+2*m-2,x);    end;    for i:=1 to n-1 do      for j:=1 to m-1 do      begin        read(x);        add(2*(i-1)*(m-1)+2*j-1,2*(i-1)*(m-1)+2*j,x);      end;  end;  procedure spfa;  var    head,tail,i,u:longint;  begin    fillchar(d,sizeof(d),$7f div 3);    d[s]:=0;    fillchar(v,sizeof(v),true);    v[s]:=false;    head:=0;    tail:=1;    state[1]:=s;    repeat      inc(head);      if head>t+7 then head:=1;      u:=state[head];      i:=last[u];      while i>0 do        with side[i] do        begin          if d[x]+z<d[y] then          begin            d[y]:=d[x]+z;            if v[y] then            begin              v[y]:=false;              inc(tail);              if tail>t+7 then tail:=1;              state[tail]:=y;            end;          end;          i:=next;        end;      v[u]:=true;    until head=tail;    writeln(d[t]);  end;  begin    init;    if flag then spfa;  end.