Bubble sort is the infamous algorithm that university students often learn as their first sorting algorithm. In terms of performance and runtime complexity, it is certainly among the worst ways to sort a collection, but it's great for teaching.
The principle is simple: walk through an array, scanning two elements and bringing them into the correct order by swapping. Repeat these steps until no swaps occur. The following diagram shows this process on the example array [8, 9, 7, 6], where a total of four swaps establishes the order of [6, 7, 8, 9] by repeatedly comparing two succeeding elements:
This diagram also shows an interesting (and name-giving) property of the algorithm: the "bubbling up" of elements to their intended position. The number 6 in the diagram travels, swap by swap, from the last position to the first position in the collection.
When this is transformed into Rust code, the simplicity remains: two nested loops iterate over the collection, whereas...
