2821: 作诗(Poetize)

2821: 作诗(Poetize)

Time Limit: 50 Sec  Memory Limit: 128 MB
Submit: 1078  Solved: 348
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Description

神犇SJY虐完HEOI之后给傻×LYD出了一题：
SHY是T国的公主，平时的一大爱好是作诗。
由于时间紧迫，SHY作完诗之后还要虐OI，于是SHY找来一篇长度为N的文章，阅读M次，每次只阅读其中连续的一段[l,r]，从这一段中选出一些汉字构成诗。因为SHY喜欢对偶，所以SHY规定最后选出的每个汉字都必须在[l,r]里出现了正偶数次。而且SHY认为选出的汉字的种类数（两个一样的汉字称为同一种）越多越好（为了拿到更多的素材！）。于是SHY请LYD安排选法。
LYD这种傻×当然不会了，于是向你请教……
问题简述：N个数，M组询问，每次问[l,r]中有多少个数出现正偶数次。

Input

输入第一行三个整数n、c以及m。表示文章字数、汉字的种类数、要选择M次。
第二行有n个整数，每个数Ai在[1, c]间，代表一个编码为Ai的汉字。
接下来m行每行两个整数l和r，设上一个询问的答案为ans(第一个询问时ans=0)，令L=(l+ans)mod n+1, R=(r+ans)mod n+1，若L>R，交换L和R，则本次询问为[L,R]。

Output

输出共m行，每行一个整数，第i个数表示SHY第i次能选出的汉字的最多种类数。

Sample Input

5 3 5
1 2 2 3 1
0 4
1 2
2 2
2 3
3 5

Sample Output

2
0
0
0
1

HINT

对于100%的数据，1<=n,c,m<=10^5

Source

By lydrainbowcat

挖个坑，以后来填。。。

本来用这题来练分块的，结果完全被二分坑到了QAQ。。。TLE...哪天有空A了这题

我的代码：

1.二分自己yy的

 {$inline on}
 const maxn=+;
 type node=record
      p,v:longint;
      end;
 var b:array[..maxn] of node;
     a,belong,v,head,tail:array[..maxn] of longint;
     mark:array[..maxn] of boolean;
     f:array[..,..] of longint;
     l,r:array[..] of longint;
     i,j,n,m,tot,ans,ll,rr,block,cnt,x:longint;
 function max(x,y:longint):longint;inline;
  begin
  if x>y then exit(x) else exit(y);
  end;
 procedure swap(var x,y:longint);inline;
  var t:longint;
  begin
  t:=x;x:=y;y:=t;
  end;

 function cmp(x,y:node):boolean;inline;
  begin
   if x.v=y.v then exit(x.p<y.p) else exit(x.v<y.v);
  end;
 procedure sort(l,r:longint);inline;
  var i,j:longint;x,y:node;
  begin
    i:=l;j:=r;x:=b[(i+j)>>];
    repeat
      while cmp(b[i],x) do inc(i);
      while cmp(x,b[j]) do dec(j);
      if i<=j then
       begin
         y:=b[i];b[i]:=b[j];b[j]:=y;
         inc(i);dec(j);
       end;
    until i>j;
    if i<r then sort(i,r);
    if j>l then sort(l,j);
  end;
 procedure init;
  begin
    readln(n,m,m);
    for i:= to n do
     begin
       read(a[i]);
       b[i].p:=i;b[i].v:=a[i];
     end;
    readln;
    sort(,n);
    block:=trunc(sqrt(n)*ln(n)/ln());
    cnt:=(n-) div block+;
    for i:= to n do belong[i]:=(i-) div block+;
    for i:= to cnt do
     begin
       l[i]:=(i-)*block+;r[i]:=i*block;
     end;
    r[cnt]:=n;
    for i:= to n do
     begin
      x:=b[i].v;
      if head[x]= then head[x]:=i;
      tail[x]:=i;
     end;
  end;
 procedure prepare;
  begin
   for i:= to cnt do
    begin
      fillchar(v,sizeof(v),);
      tot:=;
      for j:=l[i] to r[cnt] do
       begin
        inc(v[a[j]]);
        if (v[a[j]] and =) and (v[a[j]]<>) then dec(tot)
        else if v[a[j]] and = then inc(tot);
        f[i,belong[j]]:=tot;
       end;
    end;
  end;
 function findup(z,x:longint):longint;inline;
  var l,r,mid:longint;
  begin
   if x>=b[tail[z]].p then exit(tail[z]);
   l:=head[z];r:=tail[z];
   while l<r do
    begin
     mid:=(l+r)>>;
     if b[mid].p<x then l:=mid+
     else if b[mid].p>x then r:=mid
     else exit(mid);
    end;
   exit(l-);
  end;
 function finddown(z,x:longint):longint;inline;
  var l,r,mid:longint;
  begin
   l:=head[z];r:=tail[z];
   while l<r do
    begin
     mid:=(l+r)>>;
     if b[mid].p<x then l:=mid+
     else if b[mid].p>x then r:=mid
     else exit(mid);
    end;
   exit(l);
  end;

 function find(z,x,y:longint):longint;inline;
  begin
   find:=max(findup(z,y)-finddown(z,x)+,);
  end;
 procedure query(x,y:longint);inline;
  var i,bx,by,t1,t2,z:longint;
  begin
  ans:=;
  bx:=belong[x];by:=belong[y];
  if by-bx<= then
    begin
      fillchar(v,sizeof(v),);
      for i:=x to y do
       begin
        inc(v[a[i]]);
        if (v[a[i]] and =) and (v[a[i]]<>) then dec(ans)
        else if v[a[i]] and = then inc(ans);
       end;
    end
  else
    begin
      fillchar(mark,sizeof(mark),false);
      ans:=f[bx+,by-];
      for i:=x to r[bx] do
       begin
        z:=a[i];if mark[z] then continue;mark[z]:=true;
        t1:=find(z,x,y);t2:=find(z,l[bx+],r[by-]);
        if (t1 and =) and (t2 and =) and (t2<>) then dec(ans)
        else if (t1 and =) and ((t2 and =) or (t2=)) then inc(ans);
       end;
      for i:=l[by] to y do
       begin
        z:=a[i];if mark[z] then continue;mark[z]:=true;
        t1:=find(z,x,y);t2:=find(z,l[bx+],r[by-]);
        if (t1 and =) and (t2 and =) and (t2<>) then dec(ans)
        else if (t1 and =) and ((t2 and =) or (t2=)) then inc(ans);
       end;
    end;
  end;
 procedure main;
  begin
    ans:=;
    for i:= to m do
     begin
       readln(ll,rr);
       ll:=(ll+ans) mod n+;rr:=(rr+ans) mod n+;
       if ll>rr then swap(ll,rr);
       query(ll,rr);
       writeln(ans);
     end;
  end;

 begin
   assign(input,'input.txt');assign(output,'output.txt');
   reset(input);rewrite(output);
   init;
   prepare;
   main;
   close(input);close(output);
 end.    

2.二分摘抄自hzwer

 {$inline on}
 const maxn=+;
 type node=record
      p,v:longint;
      end;
 var b:array[..maxn] of node;
     a,belong,v,head,tail:array[..maxn] of longint;
     mark:array[..maxn] of boolean;
     f:array[..,..] of longint;
     l,r:array[..] of longint;
     i,j,n,m,tot,ans,ll,rr,block,cnt,x:longint;
 function max(x,y:longint):longint;inline;
  begin
  if x>y then exit(x) else exit(y);
  end;
 procedure swap(var x,y:longint);inline;
  var t:longint;
  begin
  t:=x;x:=y;y:=t;
  end;

 function cmp(x,y:node):boolean;inline;
  begin
   if x.v=y.v then exit(x.p<y.p) else exit(x.v<y.v);
  end;
 procedure sort(l,r:longint);inline;
  var i,j:longint;x,y:node;
  begin
    i:=l;j:=r;x:=b[(i+j)>>];
    repeat
      while cmp(b[i],x) do inc(i);
      while cmp(x,b[j]) do dec(j);
      if i<=j then
       begin
         y:=b[i];b[i]:=b[j];b[j]:=y;
         inc(i);dec(j);
       end;
    until i>j;
    if i<r then sort(i,r);
    if j>l then sort(l,j);
  end;
 procedure init;
  begin
    readln(n,m,m);
    for i:= to n do
     begin
       read(a[i]);
       b[i].p:=i;b[i].v:=a[i];
     end;
    readln;
    sort(,n);
    block:=trunc(sqrt(n)*ln(n)/ln());
    cnt:=(n-) div block+;
    for i:= to n do belong[i]:=(i-) div block+;
    for i:= to cnt do
     begin
       l[i]:=(i-)*block+;r[i]:=i*block;
     end;
    r[cnt]:=n;
    for i:= to n do
     begin
      x:=b[i].v;
      if head[x]= then head[x]:=i;
      tail[x]:=i;
     end;
  end;
 procedure prepare;
  begin
   for i:= to cnt do
    begin
      fillchar(v,sizeof(v),);
      tot:=;
      for j:=l[i] to r[cnt] do
       begin
        inc(v[a[j]]);
        if (v[a[j]] and =) and (v[a[j]]<>) then dec(tot)
        else if v[a[j]] and = then inc(tot);
        f[i,belong[j]]:=tot;
       end;
    end;
  end;
 function findup(z,x:longint):longint;inline;
  var l,r,mid,tmp:longint;
  begin
   l:=head[z];r:=tail[z];tmp:=;
   while l<=r do
    begin
     mid:=(l+r)>>;
     if b[mid].p>x then l:=mid+
     else begin tmp:=mid;r:=mid-;end;
    end;
   exit(tmp);
  end;
 function finddown(z,x:longint):longint;inline;
  var l,r,mid,tmp:longint;
  begin
   l:=head[z];r:=tail[z];tmp:=maxlongint;
   while l<=r do
    begin
     mid:=(l+r)>>;
     if b[mid].p<x then l:=mid+
     else begin tmp:=mid;r:=mid-;end;
    end;
   exit(tmp);
  end;

 function find(z,x,y:longint):longint;inline;
  begin
   find:=max(findup(z,y)-finddown(z,x)+,);
  end;
 procedure query(x,y:longint);inline;
  var i,bx,by,t1,t2,z:longint;
  begin
  ans:=;
  bx:=belong[x];by:=belong[y];
  if by-bx<= then
    begin
      fillchar(v,sizeof(v),);
      for i:=x to y do
       begin
        inc(v[a[i]]);
        if (v[a[i]] and =) and (v[a[i]]<>) then dec(ans)
        else if v[a[i]] and = then inc(ans);
       end;
    end
  else
    begin
      fillchar(mark,sizeof(mark),false);
      ans:=f[bx+,by-];
      for i:=x to r[bx] do
       begin
        z:=a[i];if mark[z] then continue;mark[z]:=true;
        t1:=find(z,x,y);t2:=find(z,l[bx+],r[by-]);
        if (t1 and =) and (t2 and =) and (t2<>) then dec(ans)
        else if (t1 and =) and ((t2 and =) or (t2=)) then inc(ans);
       end;
      for i:=l[by] to y do
       begin
        z:=a[i];if mark[z] then continue;mark[z]:=true;
        t1:=find(z,x,y);t2:=find(z,l[bx+],r[by-]);
        if (t1 and =) and (t2 and =) and (t2<>) then dec(ans)
        else if (t1 and =) and ((t2 and =) or (t2=)) then inc(ans);
       end;
    end;
  end;
 procedure main;
  begin
    ans:=;
    for i:= to m do
     begin
       readln(ll,rr);
       ll:=(ll+ans) mod n+;rr:=(rr+ans) mod n+;
       if ll>rr then swap(ll,rr);
       query(ll,rr);
       writeln(ans);
     end;
  end;

 begin
   assign(input,'input.txt');assign(output,'output.txt');
   reset(input);rewrite(output);
   init;
   prepare;
   main;
   close(input);close(output);
 end.