Python中如何实现回文数的判断? Leetcode上的回文数题目有哪些解题思路? 题目大意 判断一个整数(integer)是否是回文,不要使用额外的空间。 解题思路 大概就是告诉我们: 1,负数都不是回文数; 2,不能通过将数字转为字符串来判断回文,因为使用了额外的空间(即只能使用空间复杂度 O(1) 的方法); 3,注意整数溢出问...
所谓回文数 Palindrome Number,即从左边开始读或从右边开始读,两者结果一致。判断的目标数字为整数,包括负数。 比如12321,123321,或者 3,都是回文数。 -12321不是回文数;-1也不是回文数。 解法1. 简单解法:将整数转换为字符串 转换之后,Python有转换的 reverse 函数,将字符串进行反转:str[::-1]。 代码如下: ...
leetcode:Palindrome Number【Python版】 一次AC 题目要求中有空间限制,因此没有采用字符串由量变向中间逐个对比的方法,而是采用计算翻转之后的数字与x是否相等的方法; 1classSolution:2#@return a boolean3defisPalindrome(self, x):4o =x5ret =06flag = 17ifx <0:8returnFalse9while(x!=0):10ret = ret*...
print(is_palindrome_number1(num4)) print(is_palindrome_number1(num5)) print(is_palindrome_number1(num6))
Python code to check if a number is a palindrome using iteration: def is_palindrome(num): str_num = str(num) start = 0 end = len(str_num) - 1 while start < end: if str_num[start] != str_num[end]: return False start += 1 end -= 1 return True print(is_palindrome(121)) ...
Palindrome Number [回文数] Python3 Description 点击查看题目 Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward. Example 1: Input: 121 Output: true Example 2: Input: -121 Output: false Explanation: From left to right, it ...
python # 基于数学取模比较值,参考整数反转 def is_palindrome_number(num: int) -> bool: """ :param num: int32 >0 :return: bool """ INT_MAX = pow(2, 31) - 1 numOrigin = num if num < 0 or num > INT_MAX: return False ...
leetcode:Palindrome Number【Python版】 一次AC 题目要求中有空间限制,因此没有采用字符串由量变向中间逐个对比的方法,而是采用计算翻转之后的数字与x是否相等的方法; 1classSolution:2#@return a boolean3defisPalindrome(self, x):4o =x5ret =06flag = 17ifx <0:8returnFalse9while(x!=0):10ret = ret*...
publicbooleanisPalindrome1(intx){if(x ==0)returntrue;// in leetcode, negative numbers and numbers with ending zeros// are not palindromeif(x <0|| x %10==0)returnfalse;// reverse half of the number// the exit condition is y >= x// so that overflow is avoided.inty=0;while(y ...
We will simply convert the number into string and then using reversed(string) predefined function in python ,we will check whether the reversed string is same as the number or not. Algorithm/Steps The following are the algorithm/steps to print Palindrome numbers from the givenPython list: ...