POJ 1088（滑雪）

标准记忆化搜索 模板题

Program P1088;
var
   ans,n,m,i,j:longint;
   a,f:array[0..101,0..101] of longint;
function max(a,b:longint):longint;
begin
   if a>b then exit(a) else exit(b);
end;
function dfs(x,y:longint):longint;
var
   i,j:longint;
begin
   if f[x,y]>0 then exit(f[x,y]);
   dfs:=0;
   if a[x-1,y]<a[x,y] then dfs:=max(dfs,dfs(x-1,y)+1);
   if a[x+1,y]<a[x,y] then dfs:=max(dfs,dfs(x+1,y)+1);
   if a[x,y-1]<a[x,y] then dfs:=max(dfs,dfs(x,y-1)+1);
   if a[x,y+1]<a[x,y] then dfs:=max(dfs,dfs(x,y+1)+1);
   f[x,y]:=dfs;
end;
begin
   read(n,m);
   fillchar(a,sizeof(a),127);
   for i:=1 to n do
      for j:=1 to m do
         read(a[i,j]);
   fillchar(f,sizeof(f),0);
   ans:=0;

   for i:=1 to n do
      for j:=1 to m do
      begin
         if f[i,j]=0 then ans:=max(ans,dfs(i,j));
      end;
   writeln(ans+1);
end.