Python implementation of Binary Search
kw.py
def BinarySearch(array,num,first,last):
    if(first>last):
        print("\nElement not found!")
        print("———————————————————————————————————————————")
    else:
        mid=(first+last)//2;
        if(array[mid]==num):
            print("\nElement found at index",mid+1)
            print("———————————————————————————————————————————")
        elif(array[mid]>num):
            BinarySearch(array,num,first,mid-1);
        else:
            BinarySearch(array,num,mid+1,last);

print("———————————————————————————————————————————")
print("Implementation of a Binary Search")
print("———————————————————————————————————————————")
try:
    array=[]
    n=int(input("How many numbers you want to enter "))
    if(n>0):
        for i in range(0,n):
            print("Enter Number",i+1,end=" | ")
            numbers=int(input())
            array.append(numbers)
        array.sort()
        print("\nSorted numbers",array)
        num=int(input("\nEnter the number to be searched "))
        beg=0
        end=n-1
        BinarySearch(array,num,beg,end)
    else:
        print("\nPlease enter a positive integer")
        print("———————————————————————————————————————————")
except ValueError:
    print("\nInvalid Input!\nProgram Terminated")
    print("———————————————————————————————————————————")
Output: positive test
kodingwindow@kw:~$ python3 kw.py
———————————————————————————————————————————
Implementation of a Binary Search
———————————————————————————————————————————
How many numbers you want to enter 8
Enter Number 1 | -29
Enter Number 2 | 85
Enter Number 3 | -1024
Enter Number 4 | 2048
Enter Number 5 | 596
Enter Number 6 | 100
Enter Number 7 | 65535
Enter Number 8 | 0

Sorted numbers [-1024, -29, 0, 85, 100, 596, 2048, 65535]

Enter the number to be searched 0

Element found at index 3
———————————————————————————————————————————
kodingwindow@kw:~$ 

kodingwindow@kw:~$ python3 kw.py
———————————————————————————————————————————
Implementation of a Binary Search
———————————————————————————————————————————
How many numbers you want to enter 5
Enter Number 1 | 2
Enter Number 2 | 2
Enter Number 3 | 2
Enter Number 4 | 2
Enter Number 5 | 2

Sorted numbers [2, 2, 2, 2, 2]

Enter the number to be searched 2

Element found at index 3
———————————————————————————————————————————
kodingwindow@kw:~$
Output: negative test
kodingwindow@kw:~$ python3 kw.py
———————————————————————————————————————————
Implementation of a Binary Search
———————————————————————————————————————————
How many numbers you want to enter 5
Enter Number 1 | 8
Enter Number 2 | 5
Enter Number 3 | 2
Enter Number 4 | #

Invalid Input!
Program Terminated
———————————————————————————————————————————
kodingwindow@kw:~$ 

kodingwindow@kw:~$ python3 kw.py
———————————————————————————————————————————
Implementation of a Binary Search
———————————————————————————————————————————
How many numbers you want to enter 0

Please enter a positive integer
———————————————————————————————————————————
kodingwindow@kw:~$
Comments and Reactions
What Next?
Sorting Algorithms
Advertisement