<h1 id="heading-definition">Definition</h1>
<p>Stable and unstable is depend on how sort any duplicated list.   </p>
<p>If the algorithm <strong>keeps original position</strong> of duplicated values, it is stable sort algorithm<br />If the algorithm positioned duplicated values <strong>randomly</strong>, it is unstable sort algorithm</p>
<h1 id="heading-example">Example</h1>
<p>[A,C,A,B,C,D] -&gt; [A,A,B,C,C,D]</p>
<p>raw list=[A(position 1), C(position 2), A(position 3), B, C(position 5), D]<br />stable sorted list=[A(position 1), A(position 3), B, C(position 2), C(position 5), D]<br />unstable sorted list=[A(position 3), A(position 1), B, C(position 5), C(position 2), D]   </p>
<h2 id="heading-stable-sorting">Stable Sorting</h2>
<p>Bubble Sort<br />Insertion Sort<br />Merge Sort   </p>
<h2 id="heading-unstable-sorting">Unstable Sorting</h2>
<p>Quick Sort<br />Selection sort<br />Heap Sort   </p>


# Definition

Stable and unstable is depend on how sort any duplicated list.   

If the algorithm **keeps original position** of duplicated values, it is stable sort algorithm  
If the algorithm positioned duplicated values **randomly**, it is unstable sort algorithm

# Example

[A,C,A,B,C,D] -> [A,A,B,C,C,D]

raw list=[A(position 1), C(position 2), A(position 3), B, C(position 5), D]   
stable sorted list=[A(position 1), A(position 3), B, C(position 2), C(position 5), D]   
unstable sorted list=[A(position 3), A(position 1), B, C(position 5), C(position 2), D]   

## Stable Sorting

Bubble Sort   
Insertion Sort   
Merge Sort   

## Unstable Sorting

Quick Sort  
Selection sort   
Heap Sort   
 



what is difference between stable sorts vs. unstable sorts

Definition

Example

Stable Sorting

Unstable Sorting