poj 2777 ——线段树基础

Count Color

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 16872		Accepted: 4839

Description

Chosen Problem Solving and Program design as an optional course, you are required to solve all kinds of problems. Here, we get a new problem.

There is a very long board with length L centimeter, L is a positive integer, so we can evenly divide the board into L segments, and they are labeled by 1, 2, ... L from left to right, each is 1 centimeter long. Now we have to color the board - one segment with only one color. We can do following two operations on the board:

1. "C A B C" Color the board from segment A to segment B with color C.
2. "P A B" Output the number of different colors painted between segment A and segment B (including).

In our daily life, we have very few words to describe a color (red, green, blue, yellow…), so you may assume that the total number of different colors T is very small. To make it simple, we express the names of colors as color 1, color 2, ... color T. At the beginning, the board was painted in color 1. Now the rest of problem is left to your.

Input

First line of input contains L (1 <= L <= 100000), T (1 <= T <= 30) and O (1 <= O <= 100000). Here O denotes the number of operations. Following O lines, each contains "C A B C" or "P A B" (here A, B, C are integers, and A may be larger than B) as an operation defined previously.

Output

Ouput results of the output operation in order, each line contains a number.

Sample Input

2 2 4

C 1 1 2

P 1 2

C 2 2 2

P 1 2

Sample Output

2

1

Source

POJ Monthly--2006.03.26,dodo

这里依然采用lazy思想（参看上一篇）。

type

  ji=^rec;

  rec=record

  color,l,r:longint;

  lson,rson:ji;

end;

var

  v:array[-1..30] of boolean;

  ans,i,j,k,m,n,t,s,sum:longint;

  a:ji;

  ch:char;

procedure build(var a:ji; l,r:longint);

var

  mid:longint;

begin

  new(a); a^.l:=l; a^.r:=r;

  if r>l+1 then

    begin

      mid:=(l+r)>>1;

      build(a^.lson,l,mid);

      build(a^.rson,mid,r);

    end

  else

    begin

      a^.lson:=nil;

      a^.rson:=nil;

    end;

end;



procedure down(var a:ji);

begin

  if a^.color>0 then

    begin

      if a^.lson<>nil then

        a^.lson^.color:=a^.color;

      if a^.rson<>nil then

        a^.rson^.color:=a^.color;

      a^.color:=-1;

    end;

end;



procedure insert(var a:ji; l,r,s:longint);

var

  mid:longint;

begin

  if (l<=a^.l)and(a^.r<=r) then a^.color:=s else

    begin

      down(a);

      mid:=(a^.l+a^.r)>>1;

      if l<mid then insert(a^.lson,l,r,s);

      if r>mid then insert(a^.rson,l,r,s);

    end;

end;



procedure count(var a:ji; l,r:longint);

var

  mid:longint;

begin

  v[a^.color]:=true;

  if a^.color<0 then

    begin

      mid:=(a^.l+a^.r)>>1;

      if l<mid then count(a^.lson,l,r);

      if r>mid then count(a^.rson,l,r);

    end;

end;



begin

  readln(n,sum,m);

  build(a,0,n);

  a^.color:=1;

  for i:=1 to m do

    begin

      read(ch,s,t);

      if ch='C' then

        begin

          read(k);

          insert(a,s-1,t,k);

        end

      else

        begin

          ans:=0;

          fillchar(v,sizeof(v),false);

          count(a,s-1,t);

          for j:=1 to sum do

            if v[j] then inc(ans);

          writeln(ans);

        end;

      readln;

    end;

end.