2109. Adding Spaces to a String 在指定index插空格 Example 1: Input: s = "LeetcodeHelpsMeLearn", spaces = [8,13,15] Output: "Leetcode Helps Me Learn" Example 2: Input: s = "icodeinpython", spaces = [1,5,7,9] Output: "i code in py thon" Example 3: Input: s = "spacing", spaces = [0,1,2,3,4,5,6] Output: " s p a c i n g" Constraints: 1 <= s.length <= 3 * 10^5 s 只有大小寫英文字母 1 <= spaces.length <= 3 * 10^5 0 <= spaces[i] <= s.length - 1 spaces內的值是嚴格遞增 思路： 根據spaces把範圍內的字串加到list內 最後用空格串起來 最後一組字串也要記得加 Python Code: class Solution: def addSpaces(self, s: str, spaces: List[int]) -> str: ans = [] i = 0 for space in spaces: ans.append(s[i:space]) i = space ans.append(s[i:]) return ' '.join(ans) 一開始還在for字串一個一個加 好笨 -- ※ 發信站: 批踢踢實業坊(pttsite.org.tw), 來自: 114.45.25.235 (臺灣) ※ 文章網址: https://pttsite.org.tw/Marginalman/M.1733213603.A.B5A