[BZOJ3261] 最大异或和

传送门

http://www.lydsy.com/JudgeOnline/problem.php?id=3261

题目大意

给定序列,支持一下两个操作

1:在序列结尾插入一个数1:在序列结尾插入一个数

2:给定l,r,x,求一个l<=p<=r,使x xor a[p] xor a[p+1] xor ,..., xor a[n]最大2:给定l,r,x,求一个l<=p<=r,使x~~xor~~a[p]~~xor~~a[p+1]~~xor~~,...,~~xor~~a
最大

题解

可持久化Trie树裸题

注意一点,x[0]要插入0,以x[-1]为空节点

const
maxn=1000005;
var
x,root:array[0..maxn]of longint;
son:array[0..30*maxn,0..1]of longint;
size:array[0..30*maxn]of longint;
i,j,k:longint;
n,m,len1,len2,a,b,c:longint;
cha:char;
procedure init(pre,now,a:longint);
var i,b,c:longint;
begin
size[now]:=size[pre]+1;
for i:=29 downto 1 do
begin
if (a and (1<<(i-1)))=0
then b:=0 else b:=1;
c:=b xor 1;
son[now,c]:=son[pre,c];
inc(len2); son[now,b]:=len2;
size[len2]:=size[son[pre,b]]+1;
now:=son[now,b];
pre:=son[pre,b];
end;
end;

function query(l,r,a:longint):longint;
var i,b,c,tt,val:longint;
begin
val:=0;
for i:=29 downto 1 do
begin
if (a and (1<<(i-1)))=0
then b:=0 else b:=1;
c:=b xor 1;
tt:=size[son[r,c]]-size[son[l,c]];
if tt<>0
then begin l:=son[l,c]; r:=son[r,c]; inc(val,(1<<(i-1))); end
else begin l:=son[l,b]; r:=son[r,b]; end;
end;
exit(val);
end;

begin
readln(n,m); x[0]:=0; len1:=0; len2:=0;
for i:=0 to n do
begin
if i<>0
then
begin
inc(len1);
read(x[len1]);
x[len1]:=x[len1-1] xor x[len1];
end;
inc(len2);
root[len1]:=len2;
init(root[len1-1],root[len1],x[len1]);
end;
readln;
for i:=1 to m do
begin
read(cha);
if cha='A'
then
begin
inc(len1);
readln(x[len1]);
x[len1]:=x[len1-1] xor x[len1];
inc(len2);
root[len1]:=len2;
init(root[len1-1],root[len1],x[len1]);
end
else
begin
readln(a,b,c);
writeln(query(root[a-2],root[b-1],(x[len1] xor c)));
end;
end;
end.