DSA by Mitul in C++, Python, and Java : Selection Sort

Selection sort

Here we repeatedly find the minimum element and move it to the sorted part of an array to make unsorted part sorted.

Here is our unsorted array

First we will divide it in 2 parts. Sorted and Unsorted.

We will look for every element in the unsorted array to find the minimum value

It is 1 here.

Then we will swap it

Then we will assign it in the sorted array

Again, after the 2nd iteration and swapping we will have:

After 3rd:

After the whole iteration , this is what we will be left out

The benefit of selection sort is : it is a inplace sort and thus we don't need any extra space.
Code for the Selection Sort:

def selectionSort(customList):
    for i in range(len(customList)):
        min_index = i
        for j in range(i+1, len(customList)):
            if customList[min_index] > customList[j]:
                min_index = j
        customList[i], customList[min_index] = customList[min_index], customList[i]
    print(customList)

Complexity Analysis

When to use Selection sort?

1. When we have insufficient memory.
2. Easy to implement.

Why to avoid Selection Sort?
When time is a concern.