Nav: << previous: 8.字符串转换整数 (atoi) | next: 10.正则表达式匹配 >>
Description
tab: English
<p>Given an integer <code>x</code>, return <code>true</code><em> if </em><code>x</code><em> is a </em><span data-keyword="palindrome-integer"><em><strong>palindrome</strong></em></span><em>, and </em><code>false</code><em> otherwise</em>.</p>
<p> </p>
<p><strong class="example">Example 1:</strong></p>
<pre>
<strong>Input:</strong> x = 121
<strong>Output:</strong> true
<strong>Explanation:</strong> 121 reads as 121 from left to right and from right to left.
</pre>
<p><strong class="example">Example 2:</strong></p>
<pre>
<strong>Input:</strong> x = -121
<strong>Output:</strong> false
<strong>Explanation:</strong> From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.
</pre>
<p><strong class="example">Example 3:</strong></p>
<pre>
<strong>Input:</strong> x = 10
<strong>Output:</strong> false
<strong>Explanation:</strong> Reads 01 from right to left. Therefore it is not a palindrome.
</pre>
<p> </p>
<p><strong>Constraints:</strong></p>
<ul>
<li><code>-2<sup>31</sup> <= x <= 2<sup>31</sup> - 1</code></li>
</ul>
<p> </p>
<strong>Follow up:</strong> Could you solve it without converting the integer to a string?
> [!tip]- Hint 1
>
> Beware of overflow when you reverse the integer.
---
[submissions](https://leetcode.com/problems/palindrome-number/submissions/) | [solutions](https://leetcode.com/problems/palindrome-number/solutions/)
tab: 中文
<p>给你一个整数 <code>x</code> ，如果 <code>x</code> 是一个回文整数，返回 <code>true</code> ；否则，返回 <code>false</code> 。</p>
<p><span data-keyword="palindrome-integer">回文数</span>是指正序（从左向右）和倒序（从右向左）读都是一样的整数。</p>
<ul>
<li>例如，<code>121</code> 是回文，而 <code>123</code> 不是。</li>
</ul>
<p> </p>
<p><strong>示例 1：</strong></p>
<pre>
<strong>输入：</strong>x = 121
<strong>输出：</strong>true
</pre>
<p><strong>示例 2：</strong></p>
<pre>
<strong>输入：</strong>x = -121
<strong>输出：</strong>false
<strong>解释：</strong>从左向右读, 为 -121 。 从右向左读, 为 121- 。因此它不是一个回文数。
</pre>
<p><strong>示例 3：</strong></p>
<pre>
<strong>输入：</strong>x = 10
<strong>输出：</strong>false
<strong>解释：</strong>从右向左读, 为 01 。因此它不是一个回文数。
</pre>
<p> </p>
<p><strong>提示：</strong></p>
<ul>
<li><code>-2<sup>31</sup> <= x <= 2<sup>31</sup> - 1</code></li>
</ul>
<p> </p>
<p><strong>进阶：</strong>你能不将整数转为字符串来解决这个问题吗？</p>
> [!tip]- 提示 1
>
> Beware of overflow when you reverse the integer.
---
[提交记录](https://leetcode.cn/problems/palindrome-number/submissions/) | [题解](https://leetcode.cn/problems/palindrome-number/solution/)
Solutions & Notes
properties:
note.updated:
displayName: Last Updated
note.relative_links:
displayName: Related Links
note.desc:
displayName: Description
note.grade:
displayName: Rating
note.program_language:
displayName: Language
note.time_complexity:
displayName: TC
note.space_complexity:
displayName: SC
views:
- type: table
name: Solutions & Notes
filters:
and:
- file.hasLink(this.file)
- file.tags.containsAny("leetcode/solution", "leetcode/note")
order:
- file.name
- desc
- program_language
- time_complexity
- space_complexity
- grade
- relative_links
- updated
sort:
- property: grade
direction: ASC
- property: time_complexity
direction: ASC
- property: program_language
direction: ASC
columnSize:
file.name: 104
note.space_complexity: 65
note.grade: 126
Similar Problems
properties:
note.lcTopics:
displayName: Topics
note.lcAcRate:
displayName: AC Rate
note.favorites:
displayName: Favorites
note.grade:
displayName: Rating
note.translatedTitle:
displayName: Title (CN)
note.lcDifficulty:
displayName: Difficulty
views:
- type: table
name: Similar Problems
filters:
and:
- file.hasLink(this.file)
- similarQuestions.contains(this.file)
order:
- file.name
- translatedTitle
- lcTopics
- lcDifficulty
- lcAcRate
- grade
- favorites
sort:
- property: file.name
direction: ASC
- property: lcTopics
direction: DESC
columnSize:
note.translatedTitle: 240
note.lcTopics: 347
note.lcAcRate: 75
note.grade: 122