2026-06-01 16:12:21 +08:00
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#+PROPERTY: STUDY_DECK_02
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2026-06-01 17:12:10 +08:00
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* TODO 0009. Palindrome Number :easy:
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2026-06-01 02:33:30 +08:00
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:PROPERTIES:
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2026-06-01 17:22:07 +08:00
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:NEETCODE: [[file:../../roadmap.org::*0009. Palindrome Number][0009. Palindrome Number]]
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2026-06-01 02:33:30 +08:00
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:END:
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2026-06-01 17:22:07 +08:00
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Given an integer ~x~, return ~true~/ if /~x~/ is a //*palindrome*//, and /~false~/ otherwise/.
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*Example 1:*
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#+begin_src
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Input: x = 121
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Output: true
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Explanation: 121 reads as 121 from left to right and from right to left.
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#+end_src
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*Example 2:*
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#+begin_src
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Input: x = -121
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Output: false
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Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.
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#+end_src
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*Example 3:*
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#+begin_src
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Input: x = 10
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Output: false
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Explanation: Reads 01 from right to left. Therefore it is not a palindrome.
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#+end_src
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*Constraints:*
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- ~-2^{31} <= x <= 2^{31} - 1~
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*Follow up:* Could you solve it without converting the integer to a string?
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2026-06-01 02:39:53 +08:00
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** TODO Approach
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Write your approach here.
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** TODO Python
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#+begin_src python
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2026-06-01 17:22:07 +08:00
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class Solution:
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def isPalindrome(self, x: int) -> bool:
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2026-06-01 02:39:53 +08:00
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#+end_src
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** TODO C++
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2026-06-01 02:33:30 +08:00
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#+begin_src cpp
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2026-06-01 17:22:07 +08:00
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class Solution {
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public:
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bool isPalindrome(int x) {
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}
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};
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2026-06-01 02:33:30 +08:00
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#+end_src
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