Write a python program to find the closest palindrome from a given string

Python Programming Puzzles: Exercise-93 with Solution

Write a Python program to find the closest palindrome from a given string.

Input:  
cat
Output:
cac

Input:  
madan
Output:
madam
Input: 
radivider
Output:
radividar

Input: 
madan
Output:
madam
Input: 
abc
Output:
aba

Input: 
racecbr
Output:
racecar

Sample Solution:

Python Code:

#License: https://bit.ly/3oLErEI

def test(s):
    odd = 0
    for i, c in enumerate(s):
        if c != s[~i]:
            odd += 1
    if odd % 2 == 1:
        half = odd // 2
        pal = "".join((s[i] if i < half else s[~i] for i in range(len(s))))
        return pal
    else:
        half = odd // 2
        pal = "".join((s[i] if i <= half else s[~i] for i in range(len(s))))
        return pal

s = "cat"
print("Original string:",s) 
print("Closest palindrome of the said string:")
print(test(s))
s = "madan"
print("\nOriginal string:",s) 
print("Closest palindrome of the said string:")
print(test(s))
s = "radivider"
print("Original string:",s) 
print("Closest palindrome of the said string:")
print(test(s))
s = "madan"
print("\nOriginal string:",s) 
print("Closest palindrome of the said string:")
print(test(s)) 
s = "abc"
print("Original string:",s) 
print("Closest palindrome of the said string:")
print(test(s))
s = "racecbr"
print("\nOriginal string:",s) 
print("Closest palindrome of the said string:")
print(test(s))  

Sample Output:

Original string: cat
Closest palindrome of the said string:
cac

Original string: madan
Closest palindrome of the said string:
madam
Original string: radivider
Closest palindrome of the said string:
radividar

Original string: madan
Closest palindrome of the said string:
madam
Original string: abc
Closest palindrome of the said string:
aba

Original string: racecbr
Closest palindrome of the said string:
racecar

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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Python Basic - 1: Exercise-139 with Solution

Write a Python program to find the closest palindrome number of a given integer. If there are two palindrome numbers in absolute distance return the smaller number

Sample Solution-1:

Python Code:

def test(n):
    x = n
    y = n
    while True:
        if str(x) == str(x)[::-1]:
            return x
        x -=  1
        if str(y) == str(y)[::-1]:
            return y
        y += 1
    return int(bin(n)[::-1][:-2], 2)

n = 120;
print("Original number: ", n);
print("Closest Palindrome number of the said number: ",test(n));
n = 321;
print("Original number: ", n);
print("Closest Palindrome number of the said number: ",test(n));
n = 43;
print("Original number: ", n);
print("Closest Palindrome number of the said number: ",test(n));
n = 1234;
print("Original number: ", n);
print("Closest Palindrome number of the said number: ",test(n));

Sample Output:

Original number:  120
Closest Palindrome number of the said number:  121
Original number:  321
Closest Palindrome number of the said number:  323
Original number:  43
Closest Palindrome number of the said number:  44
Original number:  1234
Closest Palindrome number of the said number:  1221

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(n):
     result = 0
     while n:
          if str(n-result)==str(n-result)[::-1]:
              return n-result
          elif str(n+result)==str(n+result)[::-1]:
              return n+result
          result+=1

n = 120;
print("Original number: ", n);
print("Closest Palindrome number of the said number: ",test(n));
n = 321;
print("Original number: ", n);
print("Closest Palindrome number of the said number: ",test(n));
n = 43;
print("Original number: ", n);
print("Closest Palindrome number of the said number: ",test(n));
n = 1234;
print("Original number: ", n);
print("Closest Palindrome number of the said number: ",test(n));

Sample Output:

Original number:  120
Closest Palindrome number of the said number:  121
Original number:  321
Closest Palindrome number of the said number:  323
Original number:  43
Closest Palindrome number of the said number:  44
Original number:  1234
Closest Palindrome number of the said number:  1221

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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