poj 2777 ——线段树基础

it2022-05-08  10

Count Color Time Limit: 1000MSMemory Limit: 65536KTotal Submissions: 16872Accepted: 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.

转载于:https://www.cnblogs.com/reflec94/archive/2011/01/22/1942108.html


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