Static or dynamic collections

Fixed-size array versus resizable list: capacity and size, appending, insertion, deletion, the cost of growing and choosing according to the need.

The outline, topic by topic

Each topic is weighted the way the exam weighs it.

Fixed-size array: what is it?
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A sequence of cells whose number is decided at creation and never changes: the space is reserved in a single block.
In C, int t[5]; reserves five integers for the whole life of the array; in Java, new int[5] likewise. A sixth value does not fit.
What does this program print?

```python
t = [4, 8]
t.append(1)
t.insert(1, 6)
t.pop()
t.remove(4)
print(t)
`
- [6, 8]
- [4, 6, 8]
- [6, 8, 1]
- [6, 1]
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[6, 8]
[4, 8], then append(1) gives [4, 8, 1], insert(1, 6) gives [4, 6, 8, 1], pop() removes the last one (1), remove(4) removes the value 4: [6, 8] is left.
In a dynamic list, len(t) gives the …, that is the number of elements, which always stays lower than or equal to the ….
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In a dynamic list, len(t) gives the size, that is the number of elements, which always stays lower than or equal to the capacity.
A list of capacity 8 holding 5 elements has a size of 5. The three free cells are ready for the next appends, with no copying.
Dynamic list: what is it?
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A sequence that grows and shrinks as items are added and removed, usually reserving more cells than it uses.
It is Python's list and Java's ArrayList. Underneath there is always a fixed-size array, replaced by a larger one when it is full.