Longest Uncommon Subsequence I - Solution & Explanation

This approach takes advantage of the fact that if two strings are identical, there are no uncommon subsequences. If they are different, the longest uncommon subsequence is the longest string itself.

• If a is equal to b, return -1 because all subsequences of a are subsequences of b and vice versa.
• If a is not equal to b, return the maximum length of a or b since the longer string itself cannot be a subsequence of the other.

This C solution uses the standard library's strcmp function to check for string equality. If the strings are equal, it returns -1. Otherwise, it uses the strlen function to find the length of the longest string and returns that as the length of the longest uncommon subsequence.

Another approach is to analyze the problem by considering the entire strings as potential subsequences and determine their existence in the other string.

• Check if one string is a subsequence of the other and vice versa.
• If neither string is a subsequence of the other, return the length of the longest string.
• If one is a subsequence of the other, then no uncommon subsequence exists, return -1.

This solution defines a helper function isSubsequence that checks if one string is a subsequence of another using two pointers. It then uses this helper in findLUSlength to check the relations between a and b.