MinChar solution 
What's a Palindrome?First, a palindrome is a word or phrase that reads the same forwards and backward. For example, "racecar" and "madam" are palindromes.The Pr

What's a Palindrome?

First, a palindrome is a word or phrase that reads the same forwards and backward. For example, "racecar" and "madam" are palindromes.

The Problem:

You're given a string s. Your job is to change some of the characters in s so that it becomes a palindrome. But, you want to make the "smallest" palindrome possible. "Smallest" here means if you compare two palindromes character by character, the one with the earlier letter in the alphabet at the first point they differ is considered smaller.

How the Code Works:

Convert to Character Array:

char[] arr = s.ToCharArray();
The code turns the input string s into an array of characters called arr. This is because it's easier to change individual characters in an array.
Two Pointers:

int left = 0; and int right = s.Length - 1;
The code sets up two "pointers," left and right. left starts at the beginning of the array, and right starts at the end.
Loop and Compare:

while (left < right)
The code loops as long as the left pointer is before the right pointer.
if (arr[left] != arr[right])
Inside the loop, it checks if the characters at the left and right positions are different.
char minchr = (char)Math.Min(arr[left], arr[right]);
If they're different, it finds the smaller of the two characters (the one that comes earlier in the alphabet).
arr[left] = arr[right] = minchr;
Then, it changes both the left and right characters to this smaller character. This ensures the string becomes a palindrome.
Move Pointers:

left++; and right--;
The left pointer moves one position to the right, and the right pointer moves one position to the left.
Create New String:

return new string(arr);
Finally, the code creates a new string from the modified character array arr and returns it.
Example:

Let's say s is "egcfe".

arr becomes ['e', 'g', 'c', 'f', 'e'].
left is 0, right is 4.
arr[0] ('e') is the same as arr[4] ('e').
left becomes 1, right becomes 3.
arr[1] ('g') is different from arr[3] ('f').
minchr is 'f'.
arr[1] and arr[3] both become 'f'.
arr is now ['e', 'f', 'c', 'f', 'e'].
left becomes 2, right becomes 2.
The loop ends.
The code returns "efcfe".
Complexity:

Time Complexity: O(n)
The code goes through the string once, so the time it takes is proportional to the length of the string.
Space Complexity: O(n)
The character array arr takes up space proportional to the length of the string.

# Code
```csharp []
public class Solution {
    public string MakeSmallestPalindrome(string s) {
         char[] arr = s.ToCharArray();
        int left = 0;
        int right = s.Length-1;

     while( left<right){
         if(arr[left] != arr[right]){
            char minchr = (char)Math.Min(arr[left],arr[right]);
           arr[left] = arr[right] = minchr;
    }
    left++;
    right--;
}
return new string(arr);
    }
}
```
['Two Pointers', 'String', 'Greedy', 'C++', 'C#']