Python: Biggest even number between two numbers inclusive

Python Programming Puzzles: Exercise-58 with Solution

Write a Python program to find the biggest even number between two numbers inclusive.

Input:
m = 12
n = 51
Output:
50
Input:
m = 1
n = 79
Output:
78
Input:
m = 47
n = 53
Output:
52
Input:
m = 100
n = 200
Output:
200

Pictorial Presentation:

Sample Solution-1:

Python Code:

def test(m, n):
    if m > n or (m == n and m % 2 == 1):
        return -1
    return n if n % 2 == 0 else n - 1

m = 12
n = 51
print("\nBiggest even number between",m,"and",n)
print(test(m, n))
m = 1
n = 79
print("\nBiggest even number between",m,"and",n)
print(test(m, n))
m = 47
n = 53
print("\nBiggest even number between",m,"and",n)
print(test(m, n))
m = 100
n = 200
print("\nBiggest even number between",m,"and",n)
print(test(m, n))

Sample Output:

Biggest even number between 12 and 51
50

Biggest even number between 1 and 79
78

Biggest even number between 47 and 53
52

Biggest even number between 100 and 200
200

Flowchart:

Visualize Python code execution:

The following tool visualize what the computer is doing step-by-step as it executes the said program:

Sample Solution-2:

Python Code:

def test(p, q):
    n = q
    while (n & 1) == 1:
        n -= 1
        if n < p:
            return -1
    return n
m = 12
n = 51
print("\nBiggest even number between",m,"and",n)
print(test(m, n))
m = 1
n = 79
print("\nBiggest even number between",m,"and",n)
print(test(m, n))
m = 47
n = 53
print("\nBiggest even number between",m,"and",n)
print(test(m, n))
m = 100
n = 200
print("\nBiggest even number between",m,"and",n)
print(test(m, n))

Sample Output:

Biggest even number between 12 and 51
50

Biggest even number between 1 and 79
78

Biggest even number between 47 and 53
52

Biggest even number between 100 and 200
200

Flowchart:

Visualize Python code execution:

The following tool visualize what the computer is doing step-by-step as it executes the said program:

Python Code Editor :

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