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Python: Closest Palindrome number of a given integer

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:

Flowchart: Python - Closest Palindrome number of a given integer.

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:

Flowchart: Python - Closest Palindrome number of a given integer.

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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Previous: Write a Python program to reverse the binary representation of an given integer and convert the reversed binary number into an integer.
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Python: Tips of the Day

Iterating over dictionaries using 'for' loops:

I am a bit puzzled by the following code: d = {'x': 1, 'y': 2, 'z': 3} for key in d: print key, 'corresponds to', d[key] What I don't understand is the key portion. How does Python recognize ...

key is just a variable name.

for key in d:

For Python 3.x:

for key, value in d.items():

For Python 2.x:

for key, value in d.iteritems():

To test for yourself, change the word key to poop.

In Python 3.x, iteritems() was replaced with simply items(), which returns a set-like view backed by the dict, like iteritems() but even better. This is also available in 2.7 as viewitems().

The operation items() will work for both 2 and 3, but in 2 it will return a list of the dictionary's (key, value) pairs, which will not reflect changes to the dict that happen after the items() call. If you want the 2.x behavior in 3.x, you can call list(d.items()).

Ref: https://bit.ly/37dm0Qo