Archive

Archive for the ‘Learning’ Category

Python Sorting Algorithm – Heap Sorting -P1


Learning : Python, Math, Algorithm
Subject: Sorting Algorithm, Heap Sort

[NOTE: To keep the code as simple as we can, We WILL NOT ADD any user input Varevecations. Assuming that our user will Enter the right inputs.]

Once I start preparing and writing the code for Heap Sorting I fond that I can’t jump to the Heap Sorting without some introductions, So in this post we will cover the Array, Binary Tree, Binary Array, Max-Heap, how to know if a given Array is in Max-Heap or not, Add node to a Max-Heap and Delete a node from a Max-heap. For all this, we will have two or three posts to cover what i think we must know.

So First:
Binary Tree: A Binary Tree is a set of Nodes and each Node may have a Maximum of TWO Childs, called Left-Child and Right-Child. Going down to the next level, each of the Child’s (the left one and the right one) again may have TWO Child’s (Left and Right) .. and so on. The last level were there is no more child’s that level is the Leaves. Here are some sample of Binary Tree’s..



All the above are Binary Tree’s, But we will talk about Three Definitions for a Binary Trees:

Full Binary Tree, Complete Binary Tree, Perfect Binary Tree

Full Binary Tree:
A Tree is a Full Binary Tree in which Every/All Nodes Except Leaf Nodes(last level) have Zero or Two Children.

Complete Binary Tree:
A Binary Tree called a {complete binary tree} in which All/Each levels are completely filled except possibly the last level has all keys as left as possible
Practical example of Complete Binary Tree is Binary Heap.

Perfect Binary Tree:
A Binary Tree is {a Perfect Binary Tree} IF all the internal nodes have Two children and all leaf nodes are at the same level.

NOTE: Every Full Binary Tree is A Complete.

FULL BINARY TREEali radwani ahradwani.com python code heap sorting binary tree FULL BINARY TRTEEali radwani ahradwani.com python code heap sorting binary tree
COMPLETE BINARY TREEali radwani ahradwani.com python code heap sorting binary tree COMPLETE BINARY TREEali radwani ahradwani.com python code heap sorting binary tree
PERFECT BINARY TREEali radwani ahradwani.com python code heap sorting binary tree PERFECT BINARY TREEali radwani ahradwani.com python code heap sorting binary tree Figure 1


Binary Tree And Array: To convert a binary tree into array or to present a Binary Tree as an Array we need to consider the following :
1. To Taking all the elements in the Binary Tree.
2. To Keeping the relations between the nodes, who is the parent and what are the childerns for each parents [Left child and Right child].

1. Taking all the elements in the Binary Tree:
So for a given tree as Figure 1:[in above example] , we can see that (A) is the First Element [Root] (First Parent) and has 2 childs (B) (Left Child) & (C) (Right Child), –> Then Element (B) as parent has Two childs (D) (Left Child) & (E) (Right Child), –> Then Element (C) as parent has Two Childs (F) (Left Child) & (G) (Right Child) .. this is the end of the tree, leaves level.

Now, IF we want to present this Tree as an Array we will start with (A) in index 0, then will write all the elements level by level, from Left to Right. So we will have the array a1 as follow:
a1 = [A,B,C,D,E,F,G]

2. Keeping the relations between the Nodes: Using the Method of filling the Array as in point One (above) we Save the relations between the Parents and Childs. For a given Array a1 = [A,B,C,D,E,F,G] we can user three formulas to know the Parent and the Childs of any given Node as following:
Assuming we are at index (x) then:
1. Left Child Index of Node (x) : 2 * x + 1
2. Right Child Index of Node (x) : 2 * x + 2
3. Parent Index of Node (x) : x//2 (absolute value of the division)

So, if we refer to a1 Array and (Figure-1), and say we want to know the childrens of node (A), Node (A) is in index [0] so:
The Left child index of Node (A) is : 2 * 0 + 1 = 0 + 1 = 1, the Element in index 1 in the Array a1[1] = B.

The Right child index of Node (A) is : 2 * 0 + 2 = 0 + 2 = 2, the Element in index 2 in the Array a1[2] = C.

The Left child index of Node (C) is : 2 * 2 + 1 = 4 + 1 = 5, the Element in index 5 in the Array a1[5] = F.

The Right child index of Node (C) is : 2 * 2 + 2 = 4 + 2 = 6, the Element in index 6 in the Array a1[6] = (G).

The Parent of Node (E) will be: 4//2 = 2, so the parent of the Element (E) is a1[2] = (B)

Heap Tree: Is a Binary Essentially an almost Complete Tree. So a Heap Tree is: Tree with All/Each levels are completely Filled except possibly the last level has all keys as left as possible. In Heap The Nodes represents as Integer Numbers.

Max-Heap: In Max-Heap Tree the Child Node is Smaller than his Parent.

Mini-Heap: In Mini-Heap Tree the Child Node is Larger than his Parent.

ali radwani python code math sorting algorithm Heap



We will stop here in this part and will start doing some coding in Python Sorting Algorithm – Heap Sorting – P2.

..:: Have Fun with Coding ::.. 🙂

To Download my Python code (.py) files Click-Here



ali radwani ahradwani.com python projects codeFollow me on Twitter..

By: Ali Radwani

Another sketch challenge: A Fish


This week sketch challenge @1hour1sketch on Twitter is to Draw a A Fish so here is my sketch using pencil then black Pen and some watercolor, it takes around 30min [off and on]. More Sketches on my Sketch page ..

you may Follow me on Twitter @h_ta3kees

Here is my sketch..

Python: Sorting Algorithm. 7- Radix Sorting


Learning : Python Coding, Math, Algorithm
Subject: Python Code to Applying Radix Sorting Algorithm

[NOTE: To keep the code as simple as we can, We WILL NOT ADD any user input Varevecations. Assuming that our user will Enter the right inputs.]

Sorting Algorithm is a way to sort a given list/Array of numbers, there are several sorting Algorithm as follow:
Type of Sorting Algorithm
1. Quick Sort. [Click to Read the Post.]
2. Bubble Sort. [Click to Read the Post.]
3. Merge Sort. [Click to Read the Post.]
4. Insertion Sort. [Click to Read the Post.]
5. Selection Sort. [Click to Read the Post.]
6. Heap Sort. [Click to Read the Post.]
7. Radix Sort. [Click to Read the Post.]
8. Bucket Sort. [Click to Read the Post.]

Here in this post we will write a function to take a given list/Array and sort it then pass it back. We assume the user will enter a serial of numbers, that he want to sort, our function will sort it using Radix Sorting Algorithm and print out the original Array and the sorted one.

Radix Sort Algorithm: In Radix Sort, we will apply coming Steps:

1. Get the Maximum Number of Digits in the Array. [length of Maximum Number]

2. Add Zeros [0] to the Left of Each Number so All Numbers in the Array will be Same Lenght.

3. Sort the Array Based on The Most Right Digit [digit index] =[-i]. This was Iteration 1.

4. Repeat Step 3, and for each Iteration We Sort based on [digit index] = [-iteration].

5. If [digit index] = 0, Thats mean we did sort until Most left Digit in the Numbers. Then we Stop the Loop.

6. Return the Array.

Coding: In our Radix Sorting Application we will have several Functions to help us completing our task. First let’s see the functions:
Main-menu: To Show the Main Menu of the Application.
header: Just a Decoration Function to Print the Header of the Application.
digits_equalizer: To Add Zeros to the Left of Each Number in the Array.
create_list: Let the User to Enter the Array.
radix_sort: Applying Radix Sorting Algorithm in a Fast-Run
radix_sort_details: Applying Radix Sorting Algorithm Step-by-Step.

Just to be a short artical, i will not go thought Functions like the def main_menu() , def create_list() and def header().

So, let’s start with digits_equalizer() Function, in Radix Sorting we start comparing all numbers based on it’s digites and sorting cording that, but if a number has three digits and another one has two, then we may face an error [index out of range], so first we will convert the array to a string and will add zero.. Here is the code..

ali radwani ahradwani.com python project code radix sorting algorithm

This Function will return two arguments, the Array after adding zeros and the maximum digits.

Now, we will write the function of Radix Sorting (Fast-Run) the details function will be a copy with some print-statement.
So here is the code..

 # Radix Sort Fast-Run Function

def radix_sort() :
    
    arr = create_list()
    temp_arr = [] 
    
    # Convert to srting and Add Zeros to left side of each number in the array.
    arr,max_d = digits_equalizer(arr)    
        
    # Loop for all digits of numbers.
    for d in range (1,max_d+1):
        # Loop for sort numbers 0 to 9.
        for sn in range (0,10):
                                    
            # Check each right digits of each number. 
            for each in arr:
                if each[-d] == str(sn):
                    temp_arr.append(each)
        arr = temp_arr
        temp_arr = []        
  
    return(arr)


End of this Post..

All Code as .py file format is available in Download Page.

..:: Have Fun with Coding ::.. 🙂

To Download my Python code (.py) files Click-Here



ali radwani ahradwani.com python projects codeFollow me on Twitter..

By: Ali Radwani

Python: Kadane’s Algorithm


Learning : Python, Algorithm, Math
Subject: Implement the Kadane’s Algorithm

Definition: Kadane’s Algorithm is to search in a one Dimensional Array [integer positive and negative numbers] for a we will largest Sum of contiguous subarray.

[NOTE: To keep the code as simple as we can, We WILL NOT ADD any user input Varevecations. Assuming that our user will Enter the right inputs.]

Algorithm To find the largest subset sum, we apply coming step:
We will use two variables:
current_max: to hold the max sum of thesub-set
start_again: will be as a flag to re-set the current_max

Algorithm:
1. Start from Element in the array index = 1, save it as start_again. Set Current_max to Array Element in index = 0.

2. Do sumation of start_again with the next element index + 1.

3. If current_max < start_again then re-set current_manx = start_again

4. If start_again < 0 then re-set start_again = 0

5. Repeat from 2 to 4 until the end of the array.

6. If we reach end of the Array, then return the current_max

More from Kadane’s Algorithm:
The aim of Kadane’s Algorithm is to return the Maximum sum of sub-set. But in our code here we will return the following:
1. Maximum sum of largest subset
2. The start Index and the End Index of the subset.
3. printing out the subset.

We will have three options in our application, as following:
1. Kadane’s Algorithm – Fast Run.
2. Kadane’s Algorithm – Step By Step.
9. Exit.

As we are doing in our Algorithms coding, we will use a Main-Menu, and a Function to help the user to enter the Array.

Coding
We will start with def create_array(): and will return the Array that the user will enter. here is the code..

Ali radwani python project code Kadane Algorithm



Now, here is the code for the Main-Menu and the Main application body. In Main application body code, we will use the while True : loop and calling the main_menu() function then with if statement we will check on the user_selection

The Main-Menu
Ali radwani python project code Kadane Algorithm
Here is the Main Application body code..

Ali radwani python project code Kadane Algorithm



Last, we will write the Function to get the Kadane’s Sum in a Fast-Run, the details one will be a copy with mode print-out statement to show the steps .. [All code is in Download Page.]
As we mentioned, Our Kadane’s function will return three things, the Grates Sum of a sub-set, and to position of that sub-set as start index and end index. Here is the code ..

Ali radwani python project code Kadane Algorithm
Here is a Run-Time screen ..

Ali radwani python project code Kadane Algorithm



We done with another Algorithm, looking forwards to solve new one in coming days.

..:: Have Fun with Coding ::.. 🙂


To Download my Python code (.py) files Click-Here



ali radwani ahradwani.com python projects codeFollow me on Twitter..

By: Ali Radwani

Another sketch challenge: Black Cheetah


This week sketch challenge @1hour1sketch on Twitter is to Draw a Black Cheetah so here is my sketch using pencil then black Pen, it takes around 50min [off and on]. More Sketches on my Sketch page ..

you may Follow me on Twitter @h_ta3kees

Here is my sketch..
ali radwani sketch doha pen pencil sketchbook

Python: Sorting Algorithm.- 4-Selection


Learning : Python coding, Math, Algorithm,
Subject: Writing Selection Sorting Algorithm in Python

[NOTE: To keep the code as simple as we can, We WILL NOT ADD any user input Varevecations. Assuming that our user will Enter the right inputs.]

Sorting Algorithm is a way to sort a given list/Array of numbers, there are several sorting Algorithm as follow:
Type of Sorting Algorithm
1. Quick Sort. [Click to Read the Post.]
2. Bubble Sort. [Click to Read the Post.]
3. Merge Sort. [Click to Read the Post.]
4. Insertion Sort. [Click to Read the Post.]
5. Selection Sort. [Click to Read the Post.]
6. Heap Sort. [Click to Read the Post.]
7. Radix Sort. [Click to Read the Post.]
8. Bucket Sort. [Click to Read the Post.]

Here in this post we will write a function to take a given list and sort it then pass it back. We assume the user will enter a serial of numbers, that he want to sort, our function will sort it using Selection Sorting Algorithm and print out the original numbers and the sorted one.

Selection Sort Algorithm: In Selection Sort, we will apply coming Steps:
1. Select the Element (e) in Index i = 0.
2. Find the Smallest Element in the Array from Index i Until index = length of Array.
3. SWAP the Smallest number in the Array with the Element (e) in index i=0.
4. Select the Element (e) in index i = i+1.
5. Repeat the Algorithm from step 2, until i+1 > length of the Array.

In our Application we will have three Functions, one to collect the Array numbers from the user. [This is the main function in all our sort applications] here is the code

ali radwani ahradwani.com python project code selection sorting algorithm


We are calling this Function within the Main Selection Sort Function.
Now we will write the Selection Sort Function .

 # Selection Sorting Function

def selection_sort(arr):    
    
    for i in range (0,len(arr)):
        e = arr[i]
        s_ind = i
        for j in range (i,len(arr)):
            if arr[j] < e :
                e = arr[j]
                s_ind = j
        
        arr[i], arr[s_ind] = arr[s_ind], arr[i]        
    
    return arr       



We will have a copy of same Function with some print-statement to show the iterations and elements in each steps. Here is the code ..

ali radwani ahradwani.com python project code selection sorting algorithm

Here is screen shot of only three iteration of the Algorithm run-time..

ali radwani ahradwani.com python project code selection sorting algorithm


We Done !! .. Another coding for Sorting Algorithms, New one will be published in coming days..

… Have fun with Coding … 🙂

To Download my Python code (.py) files Click-Here



ali radwani ahradwani.com python projects codeFollow me on Twitter..

By: Ali Radwani

Python: Sort Algorithm – 3 – Insertion Sort

June 8, 2021 2 comments

Learning : Python coding, Math, Algorithm,
Subject: Writing Merge Sorting Algorithm in Python

[NOTE: To keep the code as simple as we can, We WILL NOT ADD any user input Varevecations. Assuming that our user will Enter the right inputs.]

Sorting Algorithm is a way to sort a given list/Array of numbers, there are several sorting Algorithm as follow:
Type of Sorting Algorithm
1. Quick Sort. [Click Here]
2. Bubble Sort. [Click Here]
3. Merge Sort. [Click Here]
4. Insertion Sort. [Click Here]
5. Selection Sort. [Click Here]
6. Heap Sort. [Click Here]
7. Radix Sort. [Click Here]
8. Bucket Sort. [Click Here]

Here in this post we will write a function to take a given list and sort it then pass it back. We assume the user will enter a serial of numbers, that he want to sort, our function will sort it and print out the original numbers and the sorted one.

Insertion Sort: Steps of Insertion Sorting Algorithm are:

1. Start with index (x = 1), Compare the Element (k) in index [x] with the Element in index [x-1].
1.1 If Element in [x-1] SMALLER than Element in [x] we swap the two elements.
1.2 Once we Swap we will have new index for k , and again we will compare the (k) in (new index) with element before it (new index -1), and keep moving it to left until we stop at index [0] or we face an Element GRATER than k.

2. If the Element k GRATER than the element before it, we left k and take the Next Element (to be k) and start comparing K [in x index] with Element in [x-1] index.

3. We do this until k will be in index (length on the list)

Now starting with the codes, as our standard we follow in Sorting Algorithm Applications we will have a Main-Menu and three Items the user will chose among them, and Function to let the user to enter the Numbers [The List or the Array] to be sorted. The Options in the Main-Menu are :
1. Insertion Sort Algorithm – Fast Run.
2. Insertion Sort Algorithm – Step By Step.
9. Exit.

The Fasr-Run we call the create_list(): Function first so the user will Enter the Numbers in the Array, then the Fast-Run will show the sorted Array on the screen.
In the Step-By-Step (Option 2 in the Menu) again calling create_list(): Function first, after the user Enters the Array, we will print-out on the screen each steps of selecting the index, and index-1, the k values and when/if we will SWAP or not.
The last option in the Menu is to Exit the Application (option 9).

Now we start coding.. Here is the Main-Menu.

 # Main-Menu

def main_menu ():
    os.system('clear')    
    print('\n\n',' '*5,'******************************')
    print(' '*5,' ***','  Sorting Algorithm ',' '*1,'***')
    print(' '*5,' ***','     Insertion Sort     ',' '*1,'***')
    print(' '*5,' ***',' '*22,'***')
    print(' '*5,' ******************************\n\n')
    print(' '*7,'1. Insertion Sort Algorithm - Fast Run.')
    print(' '*7,'2. Insertion Sort Algorithm - Step By Step.')
    print(' '*7,'9. Exit.')
    
    user_choice = input('\n   Select your choice.  > ')
    return user_choice 


Here is the codes for create_list(): to collect the Array from the user..

ali radwani ahradwani.com python code project sorting algorithm insertion sort
ali radwani ahradwani.com python code project sorting algorithm insertion sort


Finaly, here is the code for the Step-by-Step running for the Insetion Sort Algorithm. It is the same copy of the Fast-Run but with some print statements to show what is happening.

ali radwani ahradwani.com python code project sorting algorithm insertion sort


We Done another coding for Sorting Algorithms, another one will be published in coming days..

… Have fun with Coding … 🙂

To Download my Python code (.py) files Click-Here



ali radwani ahradwani.com python projects codeFollow me on Twitter..

By: Ali Radwani

Project: Knapsack Problem


Learning : Python, Math, Algorithm
Subject: Solving Knapsack Problem using Python

[NOTE: To keep the code as simple as we can, We WILL NOT ADD any user input Varevecations. Assuming that our user will Enter the right inputs.]

Definition: The knapsack problem is a Problem in Combinatorial Optimization: Given a set of Items, Each with a Weight and a Value or Profit, We need to Determine the Number of Each Item to Include in a Collection so that the Total Weight is Less than or Equal to a Given Limit and the Total Value is as Large as Possible.
Source: Wikipedia

In this post we will write three Functions, The Main Menu, one to Collect the data and another to solve the problem. So first, let’s see the Main-Menu ..

# Main Menu of the Project
def main_menu ():
    os.system('clear')
    print('\n',' '*5,'******************************')
    print(' '*5,' ***','   Knapsack Problem','   '*1,'***')
    print(' '*5,' ***',' '*22,'***')
    print(' '*5,' ******************************')    
    print('\n',' '*5,"==========[ Main Menu ]==========")
    print(' '*5,' 1. About Knapsack Problem.')
    print(' '*5,' 2. Collect the Items.')
    print(' '*5,' 3. Solve the Problem.')
    print(' '*5,' 9. Exit.')

    user_choice = input("\n   Select from the Menu: > ") 

    return user_choice



Above Menu will display three option that the user can select from:
1. About Knapsack Problem. [To give simple information about what is Knapsack Problem]
2. Collect the Items. [Will ask the user to Enter the Items and their coresponding Weights and Profits.]
3. Solve the Problem. [The user will Enter the Weight limit we have then we will Solve the problem]

Now we will write the Function to collect the Data from the user we will call it def collect_items(): the user will Enter the Item Name, the Weight and the Value or Profit and will save it in a list, then will return it as item_list. Here is the code and run-time screen.

ali radwani python project Knapsack Problem Algorithm
ali radwani python project Knapsack Problem Algorithm



After Collecting the Items, the user can select Number (3) from the Menu to Solve the Knapsack Problem. First we will ask user to Enter the Weights Limit we have, then calculating the Profit over Weight for each Items. In Knapsack we select the Items based on the Max w/p for each and store the indexs in a list, and with each selection we must not exceed the weight limits. Here is the code.. ..

ali radwani python project Knapsack Problem Algorithm
ali radwani python project Knapsack Problem Algorithm



So from the above example, we can achieve the Maximum Profit with weight limits to 50Kg if we take Full Amount of Item a, and Full Amount of Item b and 0.666666666 (0.67) amount of Item c.

1 * 60 = 60
1 * 100 = 100
0.67 * 120 = 80

60 + 100 + 80 = 240

NOTE: The Weight in Knapsack Problem can be weight in kg, or Number/Amount of the item (60 bags, 100 bags ..) or any Unit.

Have fun and do some coding .. 🙂


To Download my Python code (.py) files Click-Here



Follow me on Twitter..

By: Ali Radwani

Python: Sorting Algorithm (3. Merge Sort)

June 3, 2021 3 comments

Learning : Python coding, Math, Algorithm,
Subject: Writing Merge Sorting Algorithm in Python

[NOTE: To keep the code as simple as we can, We WILL NOT ADD any user input Varevecations. Assuming that our user will Enter the right inputs.]

Sorting Algorithm is a way to sort a given list/Array of numbers, there are several sorting Algorithm as follow:
Type of Sorting Algorithm
1. Quick Sort. [Click Here]
2. Bubble Sort. [Click Here]
3. Merge Sort. [Click Here]
4. Insertion Sort. [Click Here]
5. Selection Sort. [Click Here]
6. Heap Sort. [Click Here]
7. Radix Sort. [Click Here]
8. Bucket Sort. [Click Here]

Here in this post we will write a function to take a given list and sort it then pass it back. We assume the user will enter a serial of numbers, that he want to sort, our function will sort it and print out the original numbers and the sorted one.

Merge Sort: Steps of Merge Sorting Algorithm are:

1. If the Array has 1 Element then return it.
2. If the givin Array has more than 1 Element then we Divide it into 2 Parts.
Left = from Element 0 T0 Element len(arr)//2
and Right = from Element len(arr)//2 To Element len(arr). And we keep repeating step 2 for each part.
3. Once we have All parts divided we tart merge them in a sorted order.

Coding: In this Post we will write the Function for Main-Mnu, another one to collect the Array [Not Sorted] Elements from the user, then we will write the Main Function, here we will have One to Divide the Array into parts and One to Merge the Element together again. And as we done with Quick & Bubble Sort projects we will have one Fast-Run Function and another one with Details Step-By-Step run to show the Algorithm.

NOTE: All the Code will be Available in the Download Page.

Let’s start with the Main-menu to list down three option were the user will select one among them, the menu options are: 1. Merge Sort Algorithm – Fast Run. & 2. Merge Sort Algorithm – Step By Step and the last one is 3. Exit.
Here is the code.

python code project main menu by Ali Radwani merge sort Algorithm

I will Not post the code for collecting the Array Element from the user [Find it in the .py file for this project]. Here is the code for merge_sort_divider Function, it takes two arguments the Array and the user_selection, so if the user selection is 2 (2. Merge Sort Algorithm – Step By Step) We will print-out the Dividing Steps and some other Text. [We are using If Statement to print-out Text lines]. Here is the Code ..

ali radwani python code merge sort algorithm



Now for merging function, for merging function we will have two copies, one as Fast-Run and another for Details to print-out the running Steps, this will make the Fast-Run Function short and easy to follow-up. So, here is the Fast-Run Function code for merge the two part of array returned from the merge_sort_divider. Here is the Code ..

Run time screen ..

ali radwani python code merge sort algorithm



End of Merge Sorting Algorithm.

To Download my Python code (.py) files Click-Here



Follow me on Twitter..

By: Ali Radwani

Another sketch challenge: The House


This week sketch challenge @1hour1sketch on Twitter is to Draw a House so here is my sketch using pencil then black Pen, it takes around 25min. More Sketches on my Sketch page ..

you may Follow me on Twitter @h_ta3kees

Here is my sketch..
sketch of house by ali radwani ahradwani.com black pen pencil