<s>
The	O
Wavelet	B-Data_Structure
Tree	I-Data_Structure
is	O
a	O
succinct	B-Data_Structure
data	I-Data_Structure
structure	I-Data_Structure
to	O
store	O
strings	O
in	O
compressed	O
space	O
.	O
</s>
<s>
Originally	O
introduced	O
to	O
represent	O
compressed	B-Algorithm
suffix	I-Algorithm
arrays	I-Algorithm
,	O
it	O
has	O
found	O
application	O
in	O
several	O
contexts	O
.	O
</s>
<s>
The	O
name	O
derives	O
from	O
an	O
analogy	O
with	O
the	O
wavelet	B-Algorithm
transform	I-Algorithm
for	O
signals	O
,	O
which	O
recursively	O
decomposes	O
a	O
signal	O
into	O
low-frequency	O
and	O
high-frequency	O
components	O
.	O
</s>
<s>
A	O
wavelet	B-Data_Structure
tree	I-Data_Structure
contains	O
a	O
bitmap	O
representation	O
of	O
a	O
string	O
.	O
</s>
<s>
The	O
data	O
structure	O
can	O
be	O
made	O
dynamic	O
,	O
supporting	O
insertions	O
and	O
deletions	O
at	O
arbitrary	O
points	O
of	O
the	O
string	O
;	O
this	O
feature	O
enables	O
the	O
implementation	O
of	O
dynamic	O
FM-indexes	B-Algorithm
.	O
</s>
<s>
This	O
can	O
be	O
further	O
generalized	O
,	O
allowing	O
the	O
update	O
operations	O
to	O
change	O
the	O
underlying	O
alphabet	O
:	O
the	O
Wavelet	O
Trie	B-General_Concept
exploits	O
the	O
trie	B-General_Concept
structure	O
on	O
an	O
alphabet	O
of	O
strings	O
to	O
enable	O
dynamic	O
tree	O
modifications	O
.	O
</s>
