Reduce waste , calculation

[shaiful]

To reduce the waste materials. For example: There have materials list to buy materials from the market with different size in where they need to cut them according to their size in house.

Such as:
Material name is: 75 x 25 x 5 EA
Materials standard size is available in the market is: 7 Meter, 9 meter, 12 meter, 16 meter.

You need the following size of material 75 x 25 x 5 EA.

8000 mm, 2000 mm, 950 mm, 5000 mm, 5000 mm, 1500 mm ……..

Now, You need to calculate how many standard size they need to buy from the market?

Because if they buy 7 meter it can be possible to cut 5000 mm and 2000 mm to not waste materials after cut from 7 meter. But, if they choose 9 meter to cut for 5000 mm and 2000 mm in where 2 meter will waste. You want to calculate that bit by program.

So, from the above example, we will need: ( OUTPUT)

Material Name: 75 x 25 x 5 EA
STD Size Total quantity Portions Cut
7 meter 2 5000 mm, 2000 mm
5000 mm, 1500 mm
9 meter 1 8000 mm, 950 mm

Please help me out with any idea to resolve the problem, Many thanks in advance...

[jkmyoung]

Are you only allowed to make one cut per board? eg you can't cut 9m into 5000mm, 2000mm, and 2000mm? OR 5000mm, 2000mm, and 950 mm with 1050mm waste?

Is nothing lost when you cut?

===
When doing this algorithm, are the standard sizes set, or do they change from problem to problem?

Do you need to find the optimal solution, or is close-to-optimal ok?

=====
Possible Optimal-Solution Algorithm:

Add lengths of all boards needed (in this case, adds up to 22.45 m)
Round up to the nearest meter. (assumes boards are all cut to exact meter. if not algorithm needs to change slightly.)
loop {
  Try to find board lengths that exactly match that length.
  Attempt to fit the cuts in those length.
  Return if found.

  otherwise loop(rearrange board types  (retaining same length){
    Attempt fit, return if found.  
  }
  Increase length by 1. 
}

[shaiful]

Are you only allowed to make one cut per board? eg you can't cut 9m into 5000mm, 2000mm, and 2000mm? OR 5000mm, 2000mm, and 950 mm with 1050mm waste?

Is nothing lost when you cut?

===
When doing this algorithm, are the standard sizes set, or do they change from problem to problem?

Do you need to find the optimal solution, or is close-to-optimal ok?

=====
Possible Optimal-Solution Algorithm:

Add lengths of all boards needed (in this case, adds up to 22.45 m)
Round up to the nearest meter. (assumes boards are all cut to exact meter. if not algorithm needs to change slightly.)
loop {
  Try to find board lengths that exactly match that length.
  Attempt to fit the cuts in those length.
  Return if found.

  otherwise loop(rearrange board types  (retaining same length){
    Attempt fit, return if found.  
  }
  Increase length by 1. 
}

It would be multiple cut or one cut which is depend on what material size you required.

======


STD set is always fixed.

========

Increase length by 1. Sorry cant understand that

[jkmyoung]

Increase total length (sum of all used boards) by 1 meter. It's for the next iteration in the loop.