<s>
The	O
traveling	B-Algorithm
purchaser	I-Algorithm
problem	I-Algorithm
(	O
TPP	O
)	O
is	O
an	O
NP-hard	O
problem	O
studied	O
in	O
theoretical	O
computer	O
science	O
.	O
</s>
<s>
The	O
traveling	B-Algorithm
salesman	I-Algorithm
problem	I-Algorithm
(	O
TSP	O
)	O
is	O
a	O
special	O
case	O
of	O
this	O
problem	O
.	O
</s>
<s>
The	O
problem	O
can	O
be	O
seen	O
as	O
a	O
generalization	O
of	O
the	O
traveling	B-Algorithm
salesman	I-Algorithm
problem	I-Algorithm
,	O
which	O
can	O
be	O
viewed	O
as	O
the	O
special	O
case	O
of	O
TPP	O
where	O
each	O
article	O
is	O
available	O
at	O
one	O
market	O
only	O
and	O
each	O
market	O
sells	O
only	O
one	O
item	O
.	O
</s>
<s>
Approaches	O
for	O
solving	O
the	O
traveling	B-Algorithm
purchaser	I-Algorithm
problem	I-Algorithm
include	O
dynamic	B-Algorithm
programming	I-Algorithm
and	O
tabu	B-Algorithm
search	I-Algorithm
algorithms	O
.	O
</s>
