Minimum Length of String After Deleting Similar Ends

"Minimum Length of a String After Removing Matching Characters - Problem Solution"

Given a string s consisting only of characters 'a', 'b', and 'c'. You are asked to apply the following algorithm on the string any number of times:

1. Pick a non-empty prefix from the string s where all the characters in the prefix are equal.
2. Pick a non-empty suffix from the string s where all the characters in this suffix are equal.
3. The prefix and the suffix should not intersect at any index.
4. The characters from the prefix and suffix must be the same.
5. Delete both the prefix and the suffix.
Return the minimum length of s after performing the above operation any number of times (possibly zero times).

Example Usage :

Let's consider a few examples to understand how the MinimumLength method works :

Example 1 :
Input : s = "ca"
Output : 2
Explanation : You can't remove any characters, so the string stays as is.

Example 2:
Input : s = "cabaabac"
Output : 0
Explanation : An optimal sequence of operations is:
- Take prefix = "c" and suffix = "c" and remove them, s = "abaaba".
- Take prefix = "a" and suffix = "a" and remove them, s = "baab".
- Take prefix = "b" and suffix = "b" and remove them, s = "aa".
- Take prefix = "a" and suffix = "a" and remove them, s = "".

Example 3 :
Input : s = "aabccabba"
Output : 3
Explanation : An optimal sequence of operations is:
- Take prefix = "aa" and suffix = "a" and remove them, s = "bccabb".
- Take prefix = "b" and suffix = "bb" and remove them, s = "cca".

Solution Overview : 🧾

To solve this problem, we can use a simple algorithm:

1. Check if the length of the string is greater than 1 and if the first and last characters are the same.
2. If they are the same, trim both characters from the string and repeat the process until they are different.
3. Return the length of the resulting string.

Implementation in C# :

public class Solution
{
    public int MinimumLength(string s)
    {
        Again:
        if (s.Length > 1 && s[0] == s[s.Length - 1])
        {
            s = s.Trim(s[0]);
            goto Again;
        }
        return s.Length;
    }
}

Example Usage :

Provide examples using the MinimumLength method with sample input strings and expected output.

Conclusion : 🔄

Finding the minimum length of a string after removing matching characters from the beginning and end can be efficiently solved using the above algorithm. By understanding the problem and the solution approach, you can improve your problem-solving skills and write more efficient code.