skiarea.pas

Magio牛的usaco源代码

{
PROB:skiarea
LANG:PASCAL
}

program skiarea;
const
  maxsize=500;
  dx:array[1..4]of shortint=(0,0,-1,1);
  dy:array[1..4]of shortint=(-1,1,0,0);
var
  map:array[1..maxsize,1..maxsize]of integer;
  v:array[1..maxsize,1..maxsize]of boolean;
  qx,qy:array[1..sqr(maxsize)]of word;
  m,n,i,j,hill,valley,f,r,d,p,q:longint;
  ishill,isvalley:boolean;
procedure floodfill(x,y:word);
  begin
    ishill:=true;isvalley:=true;
    f:=0;r:=1;qx[1]:=x;qy[1]:=y;v[x,y]:=true;
    repeat
      inc(f);x:=qx[f];y:=qy[f];
      for d:=1 to 4 do begin
        p:=x+dx[d];q:=y+dy[d];
        if (p>0) and (p<=m) and (q>0) and (q<=n) then
          if map[x,y]>map[p,q] then
            isvalley:=false
          else if map[x,y]<map[p,q] then
            ishill:=false
          else if not v[p,q] then begin
            inc(r);qx[r]:=p;qy[r]:=q;v[p,q]:=true;
          end;
      end;
    until f=r;
    if ishill<>isvalley then
      if ishill then inc(hill) else inc(valley);
  end;
begin
  assign(input,'skiarea.in');reset(input);
  assign(output,'skiarea.out');rewrite(output);

  read(n,m);
  for i:=1 to m do
    for j:=1 to n do
      read(map[i,j]);

  fillchar(v,sizeof(v),0);
  hill:=0;valley:=0;
  for i:=1 to m do
    for j:=1 to n do
      if not v[i,j] then
        floodfill(i,j);

  if hill>valley then writeln(hill) else writeln(valley);

  close(input);close(output);
end.