[파이썬][Leetcode][릿코드] Palindrome Number
1. 문제Permalink
9. Palindrome Number
Easy
Given an integer x, return true if x is palindrome integer.
An integer is a palindrome when it reads the same backward as forward.
- For example,
121is a palindrome while123is not.
Example 1:
Input: x = 121 Output: true Explanation: 121 reads as 121 from left to right and from right to left.
Example 2:
Input: x = -121 Output: false Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.
Example 3:
Input: x = 10 Output: false Explanation: Reads 01 from right to left. Therefore it is not a palindrome.
Constraints:
-231 <= x <= 231 - 1
Follow up: Could you solve it without converting the integer to a string?
출처: Leetcode, https://leetcode.com/
2. 해결방법 시간복잡도Permalink
- 단순 코딩 O(N)
3. 문제 해결 및 코드Permalink
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| class Solution: | |
| def isPalindrome(self, x: int) -> bool: | |
| tmp = [i for i in str(x)] | |
| if tmp == list(reversed(tmp)): return True | |
| # 뒤집어도 같다면 | |
| else: return False |
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주석을 참고하면서 이해를 돕습니다.Permalink
4. 알고리즘 및 해설Permalink
- 입력값을 문자열로 변경후 해당 문자들을 리스트로 만든다.
- 이후 해당 리스트와 해당 리스트를 뒤집은 값이 같은지 여부를 출력한다.
- reversed()를 통해 해당 리스트를 뒤집은다.
- 이때 해당 리스트로 변환하지 않으면 <list_reverseiterator object at 0xxxxxxxxxxxxx>와 같은 문구가 출력된다.