- If certain operations are requested then a data structure which fulfils those operations the most, is the one to be selected.
- There are 3 things associated with a data structure:
- Storage for each data item.
- Time to perform basic operation.
- Programming effort to implement the data structure.
- The merit of two data structures can be judged by solving the same problem using those data structures and then comparing the task completion time.
- Sometimes you will find that their performances change depending on size of data.
lvalueis the value which is on the left side of the = operator.- if
int x[5]is an array thenxis a constant and is not a validlvalue.
Lists
Lists can store elements with same data types.
| Operation Name | Description |
|---|---|
| createList() | Creates a new list |
| copy() | Sets one list of be copy of another |
| clear() | Clear a list (removes all elements) |
| insert(X, ?) | insert element X at position ? in the list |
| remove(?) | remove element at ? position in the list |
| get(?) | Get element at position ? |
| update(X, ?) | Replace element at ? by X. |
| find(X) | Determine if X is present in list |
| length() | returns the length of the list |
There are 2 approaches to pointing to certain elements.
1. using indexes.
2. using a current marker (a pointer which we can move back and forth and then perform following operations).
| Functions | Description |
|---|---|
| start() | Moves the “current” pointer to the very first element |
| tail() | Moves the “current” pointer to the very last element |
| next() | Move the current position forward one element |
| back() | Move the current position backward one element |