[hdu1754]I Hate It

来源：互联网发布：miaomiaoav永久域名编辑：程序博客网时间：2024/05/14 09:34

传送门

http://acm.hdu.edu.cn/showproblem.php?pid=1754

题目大意

单点修改+区间查询最大值

题解

注意有多组数据

var w:array[0..800005,1..3]of longint; i,j,k:longint; n,m:longint; ch:char; a,b:longint;function max(a,b:longint):longint;begin if a>b then exit(a) else exit(b);end;procedure build(a,l,r:longint);var mid:longint;begin w[a,1]:=l; w[a,2]:=r; if l=r then begin read(w[a,3]); exit; end; mid:=(l+r)>>1; build(a<<1,l,mid); build(a<<1+1,mid+1,r); w[a,3]:=max(w[a<<1,3],w[a<<1+1,3]);end;procedure update(a,b,c:longint);var mid:longint;begin if (w[a,1]=w[a,2])and(w[a,1]=b) then begin w[a,3]:=c; exit; end; mid:=(w[a,1]+w[a,2])>>1; if b<=mid then update(a<<1,b,c) else update(a<<1+1,b,c); w[a,3]:=max(w[a<<1,3],w[a<<1+1,3]);end;function query(a,l,r:longint):longint;var mid:longint;begin if (w[a,1]=l)and(w[a,2]=r) then exit(w[a,3]); mid:=(w[a,1]+w[a,2])>>1; if r<=mid then exit(query(a<<1,l,r)) else if l>mid then exit(query(a<<1+1,l,r)) else exit(max(query(a<<1,l,mid),query(a<<1+1,mid+1,r)));end;begin while not eof do begin readln(n,m); build(1,1,n); readln; for i:=1 to m do  begin   readln(ch,a,b);   if ch='U' then update(1,a,b);   if ch='Q' then writeln(query(1,a,b));  end; end;end.

0 0