You have a string made up of multiple lines, and you need to build another string from it, adding or removing leading spaces on each line so that the indentation of each line is some absolute number of spaces.

• 你有一个由多行组成的字符串，你需要从它构造另一个新的字符串，增加或移去每一行的前导空格，使得每一行的缩进由确定数量的空格组成。