Container packing
National 4 container packing looks at First-fit algorithm in particular.
For National 5 the aim is to minimise the amount of containers used.
There is no set way of doing this but one method is described below.
First- fit decreasing algorithm
The following items to be packed into boxes that can hold up to \(10kg\):
| Item | A | B | C | D | E | F | G | H | I | J |
| Weight (\(kg\)) | \(7\) | \(8\) | \(4\) | \(4\) | \(2\) | \(2\) | \(3\) | \(5\) | \(8\) | \(3\) |
| Item |
|---|
| A |
| B |
| C |
| D |
| E |
| F |
| G |
| H |
| I |
| J |
| Weight (\(kg\)) |
|---|
| \(7\) |
| \(8\) |
| \(4\) |
| \(4\) |
| \(2\) |
| \(2\) |
| \(3\) |
| \(5\) |
| \(8\) |
| \(3\) |
The first-fit decreasing algorithm puts the items in order of heaviest to lightest.
| Item | B | I | A | H | C | D | G | J | E | F |
| Weight (\(kg\)) | \(8\) | \(8\) | \(7\) | \(5\) | \(4\) | \(4\) | \(3\) | \(3\) | \(2\) | \(2\) |
| Item |
|---|
| B |
| I |
| A |
| H |
| C |
| D |
| G |
| J |
| E |
| F |
| Weight (\(kg\)) |
|---|
| \(8\) |
| \(8\) |
| \(7\) |
| \(5\) |
| \(4\) |
| \(4\) |
| \(3\) |
| \(3\) |
| \(2\) |
| \(2\) |
Now continue as you would with the first-fit algorithm by putting each item into the first container that has room for it.
The first-fit decreasing algorithm only uses five boxes.