Coding classes in Suffolk

The learner invents 200 consignments with sizes between 10 and 40 units, and containers that hold 60. The sizes add up to 4,922 units, and since each container holds 60, at least 83 containers are needed however cleverly the goods are packed. That number, the total divided by the capacity and rounded up, is a lower bound: a guaranteed floor to measure every method against.

Next fit keeps one container open and starts a new one whenever the next item does not fit. First fit tries every open container from the first. Tightest fit puts each item where it leaves the least space. First fit decreasing sorts the items largest first, then uses first fit. The first three can work as goods arrive; the last needs to see everything before it starts.

First fit decreasing uses 84 containers, just one above the floor of 83, so we know for certain it is within one container of perfect without ever finding the perfect packing. That is the power of a lower bound: it lets you judge an answer when the perfect answer is too expensive to compute. Next fit wastes 22 containers because it never goes back to fill a gap. And the last row is the surprise: sorting largest first, which helps first fit, makes next fit even worse, because the big items arrive together and each leaves a gap that nothing else will fill until much later.

Real ports are more complicated: boxes have weight as well as volume, some goods cannot travel together, and containers must also come back. The DfT table itself shows this last point: by our arithmetic, only 63.8 per cent of the container units through Felixstowe in 2025 were recorded as loaded. Packing well is only half the problem; getting the empties back where they are needed is the other.

That is why coding in 2026 is worth learning for a Suffolk teenager: it teaches you to measure how good an answer is instead of accepting that it looks right. The longer argument is in why teenagers should still learn to code in 2026.