![Quick Sort
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
51 41 21 61 81 101 46 71 105 31 91 76
qa.zariga.com
1. Divide and Conquer design.
2. It works recursively
3. Choose a Pivot element in an array
(Random)
P
i
v
o
t
4. Place this element in such a way, the
array list will get divided into two sublist
so that pivot element will be greater than
first sublist and less than other sublist](https://image.slidesharecdn.com/quicksortdemo-130511114113-phpapp01/85/Quick-sort-demo-2-320.jpg)
![Quick Sort Scanning from right to left the first
number visited that has value less than 51, thus
exchange both of them
Iteration=1
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
51 41 21 61 81 101 46 71 105 31 91 76
s
t
a
r
t
Left to right search
the number which
less that 51 swap
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
31 41 21 61 81 101 46 71 105 51 91 76qa.zariga.com
Pivot
Element](https://image.slidesharecdn.com/quicksortdemo-130511114113-phpapp01/85/Quick-sort-demo-3-320.jpg)
![Quick Sort Scanning from left to right the first
number visited that has value greater than 51, thus
exchange both of them
Iteration=2
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
31 41 21 61 81 101 46 71 105 51 91 76
s
t
a
r
t
Right to left search
51<A[n]
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
31 41 21 51 81 101 46 71 105 61 91 76
qa.zariga.com](https://image.slidesharecdn.com/quicksortdemo-130511114113-phpapp01/85/Quick-sort-demo-4-320.jpg)
![Quick Sort Scanning from right to left the first
number visited that has value less than 51, thus
exchange both of them
Iteration=3
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
31 41 21 51 81 101 46 71 105 61 91 76
s
t
a
r
t
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
31 41 21 46 81 101 51 71 105 61 91 76
qa.zariga.com](https://image.slidesharecdn.com/quicksortdemo-130511114113-phpapp01/85/Quick-sort-demo-5-320.jpg)
![Quick Sort Scanning from left to right the first
number visited that has value greater than 51, thus
exchange both of them
Iteration=4
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
31 41 21 46 81 101 51 71 105 61 91 76
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
31 41 21 46 51 101 81 71 105 61 91 76
qa.zariga.com](https://image.slidesharecdn.com/quicksortdemo-130511114113-phpapp01/85/Quick-sort-demo-6-320.jpg)
![Quick Sort Scanning from right to left the first
number visited that has value less than 51, thus
exchange both of them
Iteration=6A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
31 41 21 46 51 101 81 71 105 61 91 76
s
t
a
r
t
51 >A[n]
No Element Found
Scanning from left to right the first number visited that has value greater than 51,
thus exchange both of them
51<A[n]
No Element Found
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
31 41 21 46 51 101 81 71 105 61 91 76
qa.zariga.com](https://image.slidesharecdn.com/quicksortdemo-130511114113-phpapp01/85/Quick-sort-demo-7-320.jpg)
![Quick Sort The Number 51 is Placed
to proper Position
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
31 41 21 46 51 101 81 71 105 61 91 76
Sublist1 has value
less than 51
Sublist1 has value
greater than 51
1. The Whole Process is repeated for
both Sublist1 and Sublis2
2. The Final List what we get as Sorted
List
A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12]
21 31 41 46 51 61 71 76 81 91 101 105
qa.zariga.com](https://image.slidesharecdn.com/quicksortdemo-130511114113-phpapp01/85/Quick-sort-demo-8-320.jpg)
Quick sort demo
- 2. Quick Sort A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 51 41 21 61 81 101 46 71 105 31 91 76 qa.zariga.com 1. Divide and Conquer design. 2. It works recursively 3. Choose a Pivot element in an array (Random) P i v o t 4. Place this element in such a way, the array list will get divided into two sublist so that pivot element will be greater than first sublist and less than other sublist
- 3. Quick Sort Scanning from right to left the first number visited that has value less than 51, thus exchange both of them Iteration=1 A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 51 41 21 61 81 101 46 71 105 31 91 76 s t a r t Left to right search the number which less that 51 swap A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 31 41 21 61 81 101 46 71 105 51 91 76qa.zariga.com Pivot Element
- 4. Quick Sort Scanning from left to right the first number visited that has value greater than 51, thus exchange both of them Iteration=2 A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 31 41 21 61 81 101 46 71 105 51 91 76 s t a r t Right to left search 51<A[n] A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 31 41 21 51 81 101 46 71 105 61 91 76 qa.zariga.com
- 5. Quick Sort Scanning from right to left the first number visited that has value less than 51, thus exchange both of them Iteration=3 A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 31 41 21 51 81 101 46 71 105 61 91 76 s t a r t A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 31 41 21 46 81 101 51 71 105 61 91 76 qa.zariga.com
- 6. Quick Sort Scanning from left to right the first number visited that has value greater than 51, thus exchange both of them Iteration=4 A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 31 41 21 46 81 101 51 71 105 61 91 76 A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 31 41 21 46 51 101 81 71 105 61 91 76 qa.zariga.com
- 7. Quick Sort Scanning from right to left the first number visited that has value less than 51, thus exchange both of them Iteration=6A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 31 41 21 46 51 101 81 71 105 61 91 76 s t a r t 51 >A[n] No Element Found Scanning from left to right the first number visited that has value greater than 51, thus exchange both of them 51<A[n] No Element Found A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 31 41 21 46 51 101 81 71 105 61 91 76 qa.zariga.com
- 8. Quick Sort The Number 51 is Placed to proper Position A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 31 41 21 46 51 101 81 71 105 61 91 76 Sublist1 has value less than 51 Sublist1 has value greater than 51 1. The Whole Process is repeated for both Sublist1 and Sublis2 2. The Final List what we get as Sorted List A[0] A[1] A[2] A[3] A[4] A[5] A[6] A[7] A[8] A[10] A[11] A[12] 21 31 41 46 51 61 71 76 81 91 101 105 qa.zariga.com
- 9. Quick Sort Analysis • Worst Case O(n ) – Pivot is the Smallest or Largest element in Array • Worst Case O(nlogn ) – Each Array is divided into two equla subarray of size n/2 2 qa.zariga.com
Editor's Notes
- #3: Scanning from right to left the first number visited that has value less than 51, thus exchange both of them
- #4: Scanning from right to left the first number visited that has value less than 51, thus exchange both of them
- #5: Scanning from left to right the first number visited that has value greater than 51, thus exchange both of them
- #6: Scanning from right to left the first number visited that has value less than 51, thus exchange both of them
- #7: Scanning from left to right the first number visited that has value greater than 51, thus exchange both of them
- #8: Scanning from right to left the first number visited that has value less than 51, thus exchange both of them