Complexity analysis and algorithms for the Program Download Problem
In this paper, we consider the Program Download Problem (PDP) which is to download a set of desired programs from multiple channels. When the problem is to decide whether the download can be done by a given deadline d and each program appears in each of the n channels at most once, denoted as PDP (...
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| Vydáno v: | Journal of combinatorial optimization Ročník 29; číslo 1; s. 216 - 227 |
|---|---|
| Hlavní autoři: | , , , |
| Médium: | Journal Article |
| Jazyk: | angličtina |
| Vydáno: |
Boston
Springer US
01.01.2015
|
| Témata: | |
| ISSN: | 1382-6905, 1573-2886 |
| On-line přístup: | Získat plný text |
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| Shrnutí: | In this paper, we consider the Program Download Problem (PDP) which is to download a set of desired programs from multiple channels. When the problem is to decide whether the download can be done by a given deadline
d
and each program appears in each of the
n
channels at most once, denoted as
PDP
(
n
,
1
,
d
)
, we prove that
PDP
(
n
,
1
,
d
)
is NP-complete by a reduction from 3-SAT(3). We can extend the NP-hardness proof to
PDP
(
2
,
3
,
d
)
where there are only two channels but each program could appear in each channel at most 3 times, although
PDP
(
2
,
1
,
d
)
and
PDP
(
2
,
2
,
d
)
are both in
P
. We show that the aligned version of the problem (APDP) is polynomially solvable by reducing it to a maximum flow problem. For a different version of the problem, MPDP, where the objective is to maximize the number of program downloaded before a given deadline
d
, we prove that it is fixed-parameter tractable. Finally, we devise an approximation algorithm for
MPDP
(
2
,
p
,
d
)
,
p
≥
3
, which aims to maximize the number of desired programs downloaded in two channels. |
|---|---|
| ISSN: | 1382-6905 1573-2886 |
| DOI: | 10.1007/s10878-013-9702-0 |