bzoj1453

这是一道好题，按行建线段树，每个点维护上下边界的连通性，详细见代码注释

网上写法不一，自认为比较简单，就放出来相出来献丑吧

 var u,d:array[..,..] of longint;  //u[]上边界,d[]下边界
     s,fa,q:array[..] of longint;
     c:array[..,..] of longint;  //维护对应颜色块数
     a:array[..,..] of longint;
     j,i,n,m,x,y:longint;

 function getf(x:longint):longint;
   begin
     if fa[x]<>x then fa[x]:=getf(fa[x]);
     exit(fa[x]);
   end;

 procedure union(i,m:longint);
   var j,k1,k2,t:longint;
   begin
     c[i,]:=c[i*,]+c[i*+,];
     c[i,]:=c[i*,]+c[i*+,];
     for j:= to n do
     begin
       fa[j]:=u[i*,j];
       fa[j+n]:=d[i*,j];
       fa[j+*n]:=u[i*+,j]+*n;  //防止编号重复
       fa[j+*n]:=d[i*+,j]+*n;
     end;
     for j:= to n do
       if a[m+,j]=a[m,j] then  //子区间相邻连通块合并
       begin
         k1:=getf(fa[j+n]);
         k2:=getf(fa[j+*n]);
         if k1<>k2 then
         begin
           fa[k2]:=k1;
           dec(c[i,a[m,j]]);
         end;
       end;
     t:=;
     for j:= to n do
     begin
       k1:=getf(fa[j]); //对整个区间上边界连通性重新标号
       if s[k1]= then
       begin
         inc(t);
         q[t]:=k1;
         s[k1]:=j;
       end;
       u[i,j]:=s[k1];
       k2:=getf(fa[j+*n]); //对整个区间下边界连通性重新标号
       if s[k2]= then
       begin
         inc(t);
         q[t]:=k2;
         s[k2]:=j+n;  //防止编号重复,上边界编号1~n,下边界编号n+~2n
       end;
       d[i,j]:=s[k2];
     end;
     for j:= to t do
       s[q[j]]:=;
   end;

 procedure leaf(i,row:longint);
   var j,t:longint;
   begin
     t:=;
     c[i,]:=; c[i,]:=;
     for j:= to n do
       if (j<>) and (a[row,j]=a[row,j-]) then
       begin
         u[i,j]:=u[i,j-];
         d[i,j]:=d[i,j-];
       end
       else begin
         inc(c[i,a[row,j]]);
         u[i,j]:=j; d[i,j]:=j; //连通块以起始位置为编号,这样比较方便
       end;
   end;

 procedure build(i,l,r:longint);
   var m:longint;
   begin
     if l=r then leaf(i,l)
     else begin
       m:=(l+r) shr ;
       build(i*,l,m);
       build(i*+,m+,r);
       union(i,m);
     end;
   end;

 procedure work(i,l,r:longint);
   var m:longint;
   begin
     if l=r then leaf(i,l)
     else begin
       m:=(l+r) shr ;
       if x<=m then work(i*,l,m)
       else work(i*+,m+,r);
       union(i,m);
     end;
   end;

 begin
   readln(n);
   for i:= to n do
     for j:= to n do
       read(a[i,j]);
   build(,,n);
   readln(m);
   for i:= to m do
   begin
     readln(x,y);
     a[x,y]:=-a[x,y];
     work(,,n);
     writeln(c[,],' ',c[,]);
   end;
 end.