11-02-2013, 03:04 PM
Sorting
1Selection Sort.pdf (Size: 30.69 KB / Downloads: 171)
· Sorting and searching are among the most common
programming processes.
· We want to keep information in a sensible order.
- alphabetical order
- ascending/descending order
- order according to names, ids, years, departments etc.
· The aim of sorting algorithms is to put unordered
information in an ordered form.
· There are many sorting algorithms, such as:
- Selection Sort
- Bubble Sort
- Insertion Sort
- Merge Sort
- Quick Sort
· The first three are the foundations for faster and more
efficient algorithms.
Selection Sort
The list is divided into two sublists, sorted and unsorted,
which are divided by an imaginary wall.
We find the smallest element from the unsorted sublist
and swap it with the element at the beginning of the
unsorted data.
After each selection and swapping, the imaginary wall
between the two sublists move one element ahead,
increasing the number of sorted elements and decreasing
the number of unsorted ones.
Each time we move one element from the unsorted
sublist to the sorted sublist, we say that we have
completed a sort pass.
A list of n elements requires n-1 passes to completely
rearrange the data.