ExcelBanter

ExcelBanter (https://www.excelbanter.com/)
-   Excel Programming (https://www.excelbanter.com/excel-programming/)
-   -   how many combinations in a list equal a certain total (https://www.excelbanter.com/excel-programming/281054-how-many-combinations-list-equal-certain-total.html)

Sherrie[_2_]

how many combinations in a list equal a certain total
 
I have a list of 479 rows. Column A is a product name, column B is cost. I
need to come up with every possible combination of pruducts that equals
$100.

For instance:
Product A $100
Product B $50
Product C $38.72
Product D $20
Product E $30
Product F $50

Possible answers a
A
B+D+E
B+F
F+E+D

Each Product can be used only once so B+B wouldn't work.

PLEASE PLEASE PLEASE help!

Sherrie



Jim[_28_]

how many combinations in a list equal a certain total
 
Go to www.myweb.cableone.net/twodays
Download the "Find a numeric value" file.
--
Greeting from the Gulf Coast!
http://myweb.cableone.net/twodays
"Sherrie" wrote in message
...
I have a list of 479 rows. Column A is a product name, column B is cost. I
need to come up with every possible combination of pruducts that equals
$100.

For instance:
Product A $100
Product B $50
Product C $38.72
Product D $20
Product E $30
Product F $50

Possible answers a
A
B+D+E
B+F
F+E+D

Each Product can be used only once so B+B wouldn't work.

PLEASE PLEASE PLEASE help!

Sherrie





Tom Ogilvy

how many combinations in a list equal a certain total
 
Note that that will find one combination - not all combinations (unless the
file has been changed recently).

--
Regards,
Tom Ogilvy

"Jim" wrote in message
...
Go to www.myweb.cableone.net/twodays
Download the "Find a numeric value" file.
--
Greeting from the Gulf Coast!
http://myweb.cableone.net/twodays
"Sherrie" wrote in message
...
I have a list of 479 rows. Column A is a product name, column B is cost.

I
need to come up with every possible combination of pruducts that equals
$100.

For instance:
Product A $100
Product B $50
Product C $38.72
Product D $20
Product E $30
Product F $50

Possible answers a
A
B+D+E
B+F
F+E+D

Each Product can be used only once so B+B wouldn't work.

PLEASE PLEASE PLEASE help!

Sherrie







Jim[_28_]

how many combinations in a list equal a certain total
 
The file will find *one* solution, which may not be the first or the best
and the solution cannot be narrowed by applying criteria. It is a really
simple file that is one possible solution.

--
Greeting from the Gulf Coast!
http://myweb.cableone.net/twodays
"Tom Ogilvy" wrote in message
...
Note that that will find one combination - not all combinations (unless

the
file has been changed recently).

--
Regards,
Tom Ogilvy

"Jim" wrote in message
...
Go to www.myweb.cableone.net/twodays
Download the "Find a numeric value" file.
--
Greeting from the Gulf Coast!
http://myweb.cableone.net/twodays
"Sherrie" wrote in message
...
I have a list of 479 rows. Column A is a product name, column B is

cost.
I
need to come up with every possible combination of pruducts that

equals
$100.

For instance:
Product A $100
Product B $50
Product C $38.72
Product D $20
Product E $30
Product F $50

Possible answers a
A
B+D+E
B+F
F+E+D

Each Product can be used only once so B+B wouldn't work.

PLEASE PLEASE PLEASE help!

Sherrie









Tom Ogilvy

how many combinations in a list equal a certain total
 
There are 2^480 - 1 unique combinations to check. As a point of
comparison, there are only 8,640,000 seconds in 100 years (slightly larger
then 2^23) In otherwords, there isn't enough time to do an exhaustive
examination without even trying to look at the results.

You could come up with a list of Unique prices and reduce the number of rows
you need to examine. (so in your example, any solution that contains a B
could be another solution by replacing B with F)

Regards,
Tom Ogilvy


"Sherrie" wrote in message
...
I have a list of 479 rows. Column A is a product name, column B is cost. I
need to come up with every possible combination of pruducts that equals
$100.

For instance:
Product A $100
Product B $50
Product C $38.72
Product D $20
Product E $30
Product F $50

Possible answers a
A
B+D+E
B+F
F+E+D

Each Product can be used only once so B+B wouldn't work.

PLEASE PLEASE PLEASE help!

Sherrie





Sherrie[_2_]

how many combinations in a list equal a certain total
 
Is it possible to find ALL solutions? I'd need to be able to do that on a
daily basis for a list of 10 items.

"Jim" wrote in message
...
The file will find *one* solution, which may not be the first or the best
and the solution cannot be narrowed by applying criteria. It is a really
simple file that is one possible solution.

--
Greeting from the Gulf Coast!
http://myweb.cableone.net/twodays
"Tom Ogilvy" wrote in message
...
Note that that will find one combination - not all combinations (unless

the
file has been changed recently).

--
Regards,
Tom Ogilvy

"Jim" wrote in message
...
Go to www.myweb.cableone.net/twodays
Download the "Find a numeric value" file.
--
Greeting from the Gulf Coast!
http://myweb.cableone.net/twodays
"Sherrie" wrote in message
...
I have a list of 479 rows. Column A is a product name, column B is

cost.
I
need to come up with every possible combination of pruducts that

equals
$100.

For instance:
Product A $100
Product B $50
Product C $38.72
Product D $20
Product E $30
Product F $50

Possible answers a
A
B+D+E
B+F
F+E+D

Each Product can be used only once so B+B wouldn't work.

PLEASE PLEASE PLEASE help!

Sherrie











Jim[_28_]

how many combinations in a list equal a certain total
 
Actually, there are quite a few more than 8,640,000 seconds in a hundred
years, but who's counting?! <g
60 seconds per minute, 60 minutes per hour, 24 hours per day, 365 (or so)
days per year.
=60*60*24*365*100
--
Greeting from the Gulf Coast!
http://myweb.cableone.net/twodays
"Tom Ogilvy" wrote in message
...
There are 2^480 - 1 unique combinations to check. As a point of
comparison, there are only 8,640,000 seconds in 100 years (slightly larger
then 2^23) In otherwords, there isn't enough time to do an exhaustive
examination without even trying to look at the results.

You could come up with a list of Unique prices and reduce the number of

rows
you need to examine. (so in your example, any solution that contains a B
could be another solution by replacing B with F)

Regards,
Tom Ogilvy


"Sherrie" wrote in message
...
I have a list of 479 rows. Column A is a product name, column B is cost.

I
need to come up with every possible combination of pruducts that equals
$100.

For instance:
Product A $100
Product B $50
Product C $38.72
Product D $20
Product E $30
Product F $50

Possible answers a
A
B+D+E
B+F
F+E+D

Each Product can be used only once so B+B wouldn't work.

PLEASE PLEASE PLEASE help!

Sherrie







Tom Ogilvy

how many combinations in a list equal a certain total
 
Damn, your right, I left out the 365 in my formula (doh) - none the less,
there still isn't enough time - but isn't life so much like that <g

--
Regards,
Tom Ogilvy

"Jim" wrote in message
...
Actually, there are quite a few more than 8,640,000 seconds in a hundred
years, but who's counting?! <g
60 seconds per minute, 60 minutes per hour, 24 hours per day, 365 (or so)
days per year.
=60*60*24*365*100
--
Greeting from the Gulf Coast!
http://myweb.cableone.net/twodays
"Tom Ogilvy" wrote in message
...
There are 2^480 - 1 unique combinations to check. As a point of
comparison, there are only 8,640,000 seconds in 100 years (slightly

larger
then 2^23) In otherwords, there isn't enough time to do an exhaustive
examination without even trying to look at the results.

You could come up with a list of Unique prices and reduce the number of

rows
you need to examine. (so in your example, any solution that contains a

B
could be another solution by replacing B with F)

Regards,
Tom Ogilvy


"Sherrie" wrote in message
...
I have a list of 479 rows. Column A is a product name, column B is

cost.
I
need to come up with every possible combination of pruducts that

equals
$100.

For instance:
Product A $100
Product B $50
Product C $38.72
Product D $20
Product E $30
Product F $50

Possible answers a
A
B+D+E
B+F
F+E+D

Each Product can be used only once so B+B wouldn't work.

PLEASE PLEASE PLEASE help!

Sherrie









Harlan Grove[_5_]

how many combinations in a list equal a certain total
 
"Tom Ogilvy" wrote...
There are 2^480 - 1 unique combinations to check. As a point of
comparison, there are only 8,640,000 seconds in 100 years (slightly larger
then 2^23) . . .


Quibbles.

With 479 items, there are 2^479-1 combinations to check.

8,640,000 secons is 100 days, not years.

. . . In otherwords, there isn't enough time to do an exhaustive
examination without even trying to look at the results.

You could come up with a list of Unique prices and reduce the number of rows
you need to examine. (so in your example, any solution that contains a B
could be another solution by replacing B with F)


Add to those heuristics throwing out all individual items with prices over $100.
Also, for k = INT(100/MIN(PriceList)), k gives the largest cardinality
combinations that need to be checked. That means only 479 choose k combinations
to check. Still, this type of problem lacks practical means to achieve a
comprehensive solution.

--
Never attach files.
Snip unnecessary quoted text.
Never multipost (though crossposting is usually OK).
Don't change subject lines because it corrupts Google newsgroup archives.

Tom Ogilvy

how many combinations in a list equal a certain total
 
Quibbles.

With 479 items, there are 2^479-1 combinations to check.

Yes, don't know what I was thinking - thanks for the correction

8,640,000 secons is 100 days, not years.

Already admitted to that one

Have to think about your maximum combinations assertion - (not questioning
it) - thanks

--
Regards,
Tom Ogilvy

"Harlan Grove" wrote in message
...
"Tom Ogilvy" wrote...
There are 2^480 - 1 unique combinations to check. As a point of
comparison, there are only 8,640,000 seconds in 100 years (slightly

larger
then 2^23) . . .


Quibbles.

With 479 items, there are 2^479-1 combinations to check.

8,640,000 secons is 100 days, not years.

. . . In otherwords, there isn't enough time to do an exhaustive
examination without even trying to look at the results.

You could come up with a list of Unique prices and reduce the number of

rows
you need to examine. (so in your example, any solution that contains a B
could be another solution by replacing B with F)


Add to those heuristics throwing out all individual items with prices over

$100.
Also, for k = INT(100/MIN(PriceList)), k gives the largest cardinality
combinations that need to be checked. That means only 479 choose k

combinations
to check. Still, this type of problem lacks practical means to achieve a
comprehensive solution.

--
Never attach files.
Snip unnecessary quoted text.
Never multipost (though crossposting is usually OK).
Don't change subject lines because it corrupts Google newsgroup archives.





All times are GMT +1. The time now is 06:13 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
ExcelBanter.com