| title | difficulty | tags | source | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Palindromic Numbers |
2 |
|
|
A palindromic number is one that is the same when its digits are reversed.
For example:
- 98789 is a palindrome;
- 12344321 is a palindrome;
- 12345 is not a palindrome as it becomes 54321 when reversed.
Except for 0, a palindromic number’s leftmost digit must be non-zero.
Write a program that reads in a positive integer of up to 20 digits. You should output the smallest palindromic number that is higher than the input.
What is the largest difference between a palindromic number (of up to 20 digits) and the next highest palindromic number?
How many integers are there, between 1 and 99999 inclusive, that are not the sum of two palindromic numbers?