Program cannon;

Const   fin                     ='cannon.in';
        fout                    ='cannon.out';

Var     d,l,ld                  :array[1..100]of longint;
        a                       :array[1..10]of boolean;
        opt1,opt                :array[1..100,1..100]of longint;
        ch                      :char;
        n,m,i,j,p,top,ans,s,max :longint;

Function binva:longint;
var     i,v:longint;
begin
        v:=0;
        for i:=1 to m do v:=v shl 1+ord(a[i]);
        binva:=v;
end;

Procedure search(p,r:longint);
begin
        if r=0 then begin
                inc(top);
                d[top]:=binva;
                l[top]:=i;
        end
        else if p<=m then begin
                search(p+1,r);
                a[p]:=true;
                search(p+3,r-1);
                a[p]:=false;
        end;
end;

Function ok(a,b:longint):boolean;
begin
        ok:=(a>=b) and (a xor b=a-b);
end;

Begin
        {readin}
        assign(input,fin); reset(input);
        readln(n,m);
        for i:=1 to n do begin
                for j:=1 to m do begin
                        read(ch);
                        a[j]:=ch='P';
                end;
                ld[i]:=binva;
                readln;
        end;
        close(input);
        {main}
                {init}
        top:=0;
        fillchar(a,sizeof(a),0);
                {dp}
        if n=1 then ans:=(m-1) div 3+1
        else begin
                for i:=0 to 4 do search(1,i);
                for i:=1 to top do if ok(ld[1],d[i]) then
                for j:=1 to top do if ok(ld[2],d[j]) then
                        if d[i] or d[j]=d[i]+d[j] then opt[i,j]:=l[i]+l[j];
                for s:=3 to n do begin
                        opt1:=opt;
                        for i:=1 to top do if ok(ld[s-1],d[i]) then
                        for j:=1 to top do if ok(ld[s],d[j]) and (d[i] or d[j]=d[i]+d[j]) then begin
                                max:=0;
                                for p:=1 to top do
                                        if ok(ld[s-2],d[p]) and (d[p] or d[i] or d[j]=d[p]+d[i]+d[j]) then
                                        if max<opt1[p,i]+l[j] then max:=opt1[p,i]+l[j];
                                opt[i,j]:=max;
                        end;
                end;
                ans:=0;
                for i:=1 to top do if ok(ld[n-1],d[i]) then
                for j:=1 to top do if ok(ld[n],d[j]) and (d[i] or d[j]=d[i]+d[j]) then
                        if ans<opt[i,j] then ans:=opt[i,j];
        end;
        {printout}
        assign(output,fout); rewrite(output);
        writeln(ans);
        close(output);
End.

• 把assign去掉，这里是STDIO的 (2902) TN 2005-07-13 12:10:33
  • 提交时去掉了，结果pku上WA，我在TJU上提交是AC的，是不是加了强数据？ (0) dfg 2005-07-15 20:33:31
    • upupupupup (0) sad 2005-07-16 10:59:19
      • Re:upupupupup (0) dfg 2005-07-16 13:52:21
        • Re:upupupupup (0) sad 2005-07-18 08:07:16