Kotlin中填充二维可变列表（MutableList<MutableList<String>>）时遭遇类型不匹配问题求助

Let's break down exactly why you're hitting that type mismatch error, and how to fix it quickly.

First, your inputList is declared as MutableList<MutableList<String>>—this means every element you add to it needs to be a list of strings. But right now, two things are off in your code:

1. You declared var strings: String, but you're trying to assign a list to it (that's a mismatch right there).
2. When you do strings = "D".toString().toMutableList(), you're turning the string "D" into a MutableList<Char> (since toMutableList() on a String splits it into individual characters), not a list containing the string itself.

Here's the straightforward fix:

• Update the type of strings to match what you actually need: MutableList<String>
• Instead of converting the string to a char list, create a mutable list that holds the string "D" directly using mutableListOf("D")

Your corrected code will look like this:

fun main() {
    val inputList: MutableList<MutableList<String>> = mutableListOf()
    val n = readLine()!!.toInt()
    var strings: MutableList<String> // Fixed the variable type here
    for (i in 0 until n) {
        strings = mutableListOf("D") // Creates a list containing the string "D"
        inputList.add(strings)
    }
}

This works because mutableListOf("D") creates a MutableList<String> with exactly one element (the string "D"), which perfectly matches the type your outer inputList expects.

内容的提问来源于stack exchange，提问作者sievy