bzoj2437

  1 const dx:array[1..4] of longint=(0,0,1,-1);
  2       dy:array[1..4] of longint=(1,-1,0,0);
  3 
  4 type node=record
  5        po,next:longint;
  6      end;
  7 
  8 var e:array[0..4010] of node;
  9     v:array[0..2010] of boolean;
 10     b:array[0..50,0..50] of longint;
 11     a:array[0..50,0..50] of char;
 12     mat,p,c:array[0..2010] of longint;
 13     t,xx,yy,i,n,m,j,k,len,x,y,ans:longint;
 14     f1,f2:boolean;
 15 
 16 procedure add(x,y:longint);
 17   begin
 18     inc(len);
 19     e[len].po:=y;
 20     e[len].next:=p[x];
 21     p[x]:=len;
 22   end;
 23 
 24 function dfs(x:longint):boolean;
 25   var i,y:longint;
 26   begin
 27     v[x]:=true;
 28     i:=p[x];
 29     while i<>0 do
 30     begin
 31       y:=e[i].po;
 32       if not v[y] and (mat[y]<>-1) then
 33       begin
 34         v[y]:=true;
 35         if (mat[y]=0) or dfs(mat[y]) then
 36         begin
 37           mat[y]:=x;
 38           mat[x]:=y;
 39           exit(true);
 40         end;
 41       end;
 42       i:=e[i].next;
 43     end;
 44     exit(false);
 45   end;
 46 
 47 function check:boolean;
 48   var j,k:longint;
 49   begin
 50     k:=b[x,y];
 51     j:=mat[k];
 52     mat[j]:=0;
 53     mat[k]:=-1;
 54     if j=0 then exit(false)
 55     else begin
 56       fillchar(v,sizeof(v),false);
 57       exit(not dfs(j));
 58     end;
 59   end;
 60 
 61 begin
 62   readln(n,m);
 63   for i:=1 to n do
 64   begin
 65     for j:=1 to m do
 66     begin
 67       read(a[i,j]);
 68       if a[i,j]=‘.‘ then
 69       begin
 70         x:=i;
 71         y:=j;
 72         a[i,j]:=‘X‘;
 73       end;
 74     end;
 75     readln;
 76   end;
 77   for i:=1 to n do
 78     for j:=1 to m do
 79       if (a[i,j]=‘O‘) xor ((abs(i-x)+abs(j-y)) mod 2=0) then
 80       begin
 81         inc(t);
 82         b[i,j]:=t;
 83       end;
 84 
 85   for i:=1 to n do
 86     for j:=1 to m do
 87       if b[i,j]>0 then
 88       begin
 89         for k:=1 to 4 do
 90         begin
 91           xx:=i+dx[k];
 92           yy:=j+dy[k];
 93           if b[xx,yy]>0 then add(b[i,j],b[xx,yy]);
 94         end;
 95       end;
 96 
 97   for i:=1 to t do
 98     if mat[i]=0 then
 99     begin
100       fillchar(v,sizeof(v),false);
101       dfs(i);
102     end;
103     
104   readln(k);
105   for i:=1 to k do
106   begin
107     f1:=check;
108     readln(x,y);
109     f2:=check;
110     if f1 and f2 then
111     begin
112       inc(ans);
113       c[ans]:=i;
114     end;
115     readln(x,y);
116   end;
117   writeln(ans);
118   for i:=1 to ans do
119     writeln(c[i]);
120 end.