<s>
Coalesced	B-Algorithm
hashing	I-Algorithm
,	O
also	O
called	O
coalesced	B-Algorithm
chaining	I-Algorithm
,	O
is	O
a	O
strategy	O
of	O
collision	O
resolution	O
in	O
a	O
hash	B-Algorithm
table	I-Algorithm
that	O
forms	O
a	O
hybrid	O
of	O
separate	O
chaining	O
and	O
open	B-Algorithm
addressing	I-Algorithm
.	O
</s>
<s>
In	O
a	O
separate	O
chaining	O
hash	B-Algorithm
table	I-Algorithm
,	O
items	O
that	O
hash	O
to	O
the	O
same	O
address	O
are	O
placed	O
on	O
a	O
list	O
(	O
or	O
"	O
chain	O
"	O
)	O
at	O
that	O
address	O
.	O
</s>
<s>
However	O
,	O
sometimes	O
the	O
extra	O
memory	O
use	O
might	O
be	O
prohibitive	O
,	O
and	O
the	O
most	O
common	O
alternative	O
,	O
open	B-Algorithm
addressing	I-Algorithm
,	O
has	O
uncomfortable	O
disadvantages	O
that	O
decrease	O
performance	O
.	O
</s>
<s>
The	O
primary	O
disadvantage	O
of	O
open	B-Algorithm
addressing	I-Algorithm
is	O
primary	O
and	O
secondary	O
clustering	O
,	O
in	O
which	O
searches	O
may	O
access	O
long	O
sequences	O
of	O
used	O
buckets	O
that	O
contain	O
items	O
with	O
different	O
hash	O
addresses	O
;	O
items	O
with	O
one	O
hash	O
address	O
can	O
thus	O
lengthen	O
searches	O
for	O
items	O
with	O
other	O
hash	O
addresses	O
.	O
</s>
<s>
One	O
solution	O
to	O
these	O
issues	O
is	O
coalesced	B-Algorithm
hashing	I-Algorithm
.	O
</s>
<s>
Coalesced	B-Algorithm
hashing	I-Algorithm
uses	O
a	O
similar	O
technique	O
as	O
separate	O
chaining	O
,	O
but	O
instead	O
of	O
allocating	O
new	O
nodes	O
for	O
the	O
linked	O
list	O
,	O
buckets	O
in	O
the	O
actual	O
table	O
are	O
used	O
.	O
</s>
<s>
However	O
,	O
the	O
extent	O
of	O
coalescing	O
is	O
minor	O
compared	O
with	O
the	O
clustering	O
exhibited	O
by	O
open	B-Algorithm
addressing	I-Algorithm
.	O
</s>
<s>
For	O
example	O
,	O
when	O
coalescing	O
occurs	O
,	O
the	O
length	O
of	O
the	O
chain	O
grows	O
by	O
only	O
1	O
,	O
whereas	O
in	O
open	B-Algorithm
addressing	I-Algorithm
,	O
search	O
sequences	O
of	O
arbitrary	O
length	O
may	O
combine	O
.	O
</s>
<s>
Insertion	O
in	O
C	B-Language
:	O
</s>
<s>
One	O
benefit	O
of	O
this	O
strategy	O
is	O
that	O
the	O
search	O
algorithm	O
for	O
separate	O
chaining	O
can	O
be	O
used	O
without	O
change	O
in	O
a	O
coalesced	O
hash	B-Algorithm
table	I-Algorithm
.	O
</s>
<s>
Lookup	O
in	O
C	B-Language
:	O
</s>
<s>
Coalesced	B-Algorithm
chaining	I-Algorithm
avoids	O
the	O
effects	O
of	O
primary	O
and	O
secondary	O
clustering	O
,	O
and	O
as	O
a	O
result	O
can	O
take	O
advantage	O
of	O
the	O
efficient	O
search	O
algorithm	O
for	O
separate	O
chaining	O
.	O
</s>
<s>
As	O
in	O
open	B-Algorithm
addressing	I-Algorithm
,	O
deletion	O
from	O
a	O
coalesced	O
hash	B-Algorithm
table	I-Algorithm
is	O
awkward	O
and	O
potentially	O
expensive	O
,	O
and	O
resizing	O
the	O
table	O
is	O
terribly	O
expensive	O
and	O
should	O
be	O
done	O
rarely	O
,	O
if	O
ever	O
.	O
</s>
