LeetCode | 1374. 生成每种字符都是奇数个的字符串【Python】

LeetCode 1374. Generate a String With Characters That Have Odd Counts生成每种字符都是奇数个的字符串【Easy】【Python】【字符串】

Problem

LeetCode

Given an integer n, return a string with n characters such that each character in such string occurs *an odd number of times***.

The returned string must contain only lowercase English letters. If there are multiples valid strings, return any of them.

Example 1:

Input: n = 4
Output: "pppz"
Explanation: "pppz" is a valid string since the character 'p' occurs three times and the character 'z' occurs once. Note that there are many other valid strings such as "ohhh" and "love".

Example 2:

Input: n = 2
Output: "xy"
Explanation: "xy" is a valid string since the characters 'x' and 'y' occur once. Note that there are many other valid strings such as "ag" and "ur".

Example 3:

Input: n = 7
Output: "holasss"

Constraints:

• 1 <= n <= 500

问题

力扣

给你一个整数 n，请你返回一个含 n 个字符的字符串，其中每种字符在该字符串中都恰好出现 奇数次 。

返回的字符串必须只含小写英文字母。如果存在多个满足题目要求的字符串，则返回其中任意一个即可。

示例 1：

输入：n = 4
输出："pppz"
解释："pppz" 是一个满足题目要求的字符串，因为 'p' 出现 3 次，且 'z' 出现 1 次。当然，还有很多其他字符串也满足题目要求，比如："ohhh" 和 "love"。

示例 2：

输入：n = 2
输出："xy"
解释："xy" 是一个满足题目要求的字符串，因为 'x' 和 'y' 各出现 1 次。当然，还有很多其他字符串也满足题目要求，比如："ag" 和 "ur"。

示例 3：

输入：n = 7
输出："holasss"

提示：

• 1 <= n <= 500

思路

字符串

n 为偶数，n-1 个 'a' + 1 个 'b'
n 为奇数，n 个 'a'

时间复杂度: O(n)
空间复杂度: O(n)

Python3代码

class Solution:
    def generateTheString(self, n: int) -> str:
        res = []
        if n % 2 == 0:
            for i in range(n-1):
                res.append('a')
            res.append('b')
        else:
            for i in range(n):
                res.append('a')
        return ''.join(res)

代码地址

GitHub链接