<s>
In	O
computing	O
,	O
a	O
one-pass	B-General_Concept
algorithm	I-General_Concept
or	O
single-pass	B-General_Concept
algorithm	I-General_Concept
is	O
a	O
streaming	O
algorithm	O
which	O
reads	O
its	O
input	O
exactly	O
once	O
.	O
</s>
<s>
It	O
does	O
so	O
by	O
processing	O
items	O
in	O
order	O
,	O
without	O
unbounded	O
buffering	B-General_Concept
;	O
it	O
reads	O
a	O
block	O
into	O
an	O
input	B-General_Concept
buffer	I-General_Concept
,	O
processes	O
it	O
,	O
and	O
moves	O
the	O
result	O
into	O
an	O
output	O
buffer	B-General_Concept
for	O
each	O
step	O
in	O
the	O
process	O
.	O
</s>
<s>
A	O
one-pass	B-General_Concept
algorithm	I-General_Concept
generally	O
requires	O
O(n )	O
(	O
see	O
'	O
big	O
O	O
 '	O
notation	O
)	O
time	O
and	O
less	O
than	O
O(n )	O
storage	O
(	O
typically	O
O(1 )	O
)	O
,	O
where	O
n	O
is	O
the	O
size	O
of	O
the	O
input	O
.	O
</s>
<s>
An	O
example	O
of	O
a	O
one-pass	B-General_Concept
algorithm	I-General_Concept
is	O
the	O
Sondik	O
partially	O
observable	O
Markov	O
decision	O
process	O
.	O
</s>
<s>
Find	O
the	O
sum	O
,	O
mean	O
,	O
variance	O
and	O
standard	B-General_Concept
deviation	I-General_Concept
of	O
the	O
elements	O
of	O
the	O
list	O
.	O
</s>
<s>
See	O
also	O
Algorithms	B-Algorithm
for	I-Algorithm
calculating	I-Algorithm
variance	I-Algorithm
.	O
</s>
<s>
The	O
two-pass	O
algorithms	O
above	O
are	O
still	O
streaming	O
algorithms	O
but	O
not	O
one-pass	B-General_Concept
algorithms	I-General_Concept
.	O
</s>
