[C#][Programmers] 인덱스 바꾸기

using System;
using System.Linq;

public class Solution {
     public string solution(string my_string, int num1, int num2)
    {
        string answer = String.Concat(my_string.Where((_,x) => x != num1 && x != num2));
        answer =answer.Insert(num1, my_string[num2].ToString());
        answer =answer.Insert(num2, my_string[num1].ToString());

        return answer;
    }
}

이거 머징

using System;
using System.Linq;

public class Solution {
    public string solution(string my_string, int num1, int num2) {
        string answer = "";
        var arr = my_string.ToArray();
        char temp = arr[num1];
        arr[num1] = arr[num2];
        arr[num2] = temp;

        answer = String.Concat(arr);

        return answer;
    }
}

정석