Leetcode 2109. Adding Spaces to a String

You are given a 0-indexed string s and a 0-indexed integer array spaces that describes the indices in the original string where spaces will be added. Each space should be inserted before the character at the given index.

• For example, given s = "EnjoyYourCoffee" and spaces = [5, 9], we place spaces before 'Y' and 'C', which are at indices 5 and 9 respectively. Thus, we obtain "Enjoy Your Coffee".

Return the modified string after the spaces have been added.

Example 1:

Input: s = "LeetcodeHelpsMeLearn", spaces = [8,13,15]Output: "Leetcode Helps Me Learn"Explanation: The indices 8, 13, and 15 correspond to the underlined characters in "LeetcodeHelpsMeLearn". We then place spaces before those characters.

Example 2:

Input: s = "icodeinpython", spaces = [1,5,7,9]Output: "i code in py thon"Explanation:The indices 1, 5, 7, and 9 correspond to the underlined characters in "icodeinpython". We then place spaces before those characters.

Example 3:

Input: s = "spacing", spaces = [0,1,2,3,4,5,6]Output: " s p a c i n g"Explanation:We are also able to place spaces before the first character of the string.

Constraints:

• 1 <= s.length <= 3 * 105

• s consists only of lowercase and uppercase English letters.

• 1 <= spaces.length <= 3 * 105

• 0 <= spaces[i] <= s.length - 1

• All the values of spaces are strictly increasing.

依次遍历即可，用stringbuilder 记录，最后导出即可，不理解为什么是中等题目，不应该是简单题目吗？

Runtime: 35 ms, faster than 58.22% of Java online submissions for Adding Spaces to a String.

Memory Usage: 76.4 MB, less than 72.89% of Java online submissions for Adding Spaces to a String.

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