Check dates if palindrome

sum=0;
n1=input('Please enter first date:');

Unable to run the 'fevalJSON' function because it calls the 'input' function, which is not supported for this product offering.

n2=input('Please enter second date:');

x=n1:n2;

    for i=n1:n2
        if (n1>0)
            r=round(rem(n1,10)-0.1);
            sum=sum*10+r;
            n1=round((n1/10)-0.1);
            c1=x-sum;
        elseif (n2>0)
            r=round(rem(n2,10)-0.1);
            sum=sum*10+r;
            n2=round((n2/10)-0.1);
            c2=x-sum;
            
        end
    end
    

Im trying to write the code which is checking palindrome in the interval of dates. how can i put the limits. and then it should print all palindromes one after other.

[KSSV]

Can you show us any example?

[Delya Ochirova]

for example i want interval 01.01.1900-01.01.2023. this is my limits. program should check all dates from my input data(n1-first, n2-second) and print all palindromes

[Jan]

@Delya Ochirova: What do you call "a date" and what are typical inputs of this code? The input() command is not a good choice to explain a problem. Prefer posting explicit example data.

Avoid to use "sum" as a name of a variable, because this causes troubles, if you want to use the function with the same name later.

[Jan]

Okay. How yould you use input() to get something like "01.01.1900" ? What do you call a palindrome of e.g. "01.01.1900"? "0091.10.10" is not an option, so please define exactly, what you want.

Because I dared to guess, what you want, I've wasted some time already withwriting a not matching answer.

Answer 1

[KSSV]

t = datetime(2023,3,20) ;
t.Format = 'Mddyy' ;

if isPalindrome(char(t))
    fprintf('%s is a Palindrome\n',char(t))
end

32023 is a Palindrome

function output = isPalindrome(yourString)
reverseString = flip(yourString) ;
if strcmp(yourString,reverseString)
    output = true;
else
    output = false;
end


end

[Jan]

strcmp(yourString,yourString) is always true.

A simplification and correction:

function output = isPalindrome(yourString)
output = strcmp(yourString, flip(yourString));
end

[KSSV]

@Jan Aboslutely yes. I missed this.

[Jan]

The pattern:

if condition
    result = true;
else
    result = false;
end

can be simplified in general to:

result = condition;

which is even faster.

Answer 2

[Image Analyst]

Are you considering month/day/year separators to be included in the string? Try this where I do it both ways.

% Get user's date:
date1 = input('Please enter first date:', 's');

% Now see if it's a palindrome leaving the separators in.
if isequal(date1, flip(date1))
    fprintf('"%s" is a palindrome date with using separators.\n', date1);
else
    fprintf('"%s" is not a palindrome date with using separators.\n', date1);
end

% Now see if it's a palindrome with numbers only,
% ignoring the separators.
pat = digitsPattern;
numbersOnly = join(extract(date1, pat));
numbersOnly = strrep(numbersOnly{1}, ' ', '');
if isequal(numbersOnly, flip(numbersOnly))
    fprintf('"%s" is a palindrome date without using separators because it is %s.\n', date1, numbersOnly);
else
    fprintf('"%s" is not a palindrome date without using separators because it is %s.\n', date1, numbersOnly);
end

Here are some examples:

Please enter first date:2/2/2022

"2/2/2022" is not a palindrome date with using separators.

"2/2/2022" is not a palindrome date without using separators because it is 222022.

Please enter first date:1/11/11

"1/11/11" is not a palindrome date with using separators.

"1/11/11" is a palindrome date without using separators because it is 11111.

Answer 3

[Delya Ochirova]

close all
clear
clc

t1=input('First date:');
t2=input('Second date:');

format='ddmmyyyy';
n1=datenum(t1,format);
n2=datenum(t2,format);

for i=n1:n2
    n3=datestr(i,format);
    if n3==fliplr(n3)
        fprintf ('Palindrome dates:%s\n', n3)
    end
end

i dont understand why its not working.

[Jan]

If it does not work, this is not an answer.

I asked you 3 days ago, what you call a palindrom e.g. for the input "01.01.1900". It would be much easier to help you, if you mention at least, what you exactly want. Posting some code, which does not work, is not useful.

The readers cannot know, what you input as n1 and n2.