Find the Difference - Solution & Explanation

This approach involves creating frequency counts for both strings. Loop through each character in both strings, updating a counter for each character. By comparing these counters, you can determine which character has a different count, revealing the additional character in string t.

This solution initializes an array of size 26 (for each letter in the English alphabet) to zero. It then iterates over string s, incrementing the count for each letter. It subsequently iterates over string t, decrementing the count. The first character that results in a non-positive count is the additional character.

This approach leverages the properties of the XOR bitwise operator. XOR'ing the same numbers results in 0 and XOR is commutative and associative, meaning the order of operations doesn't matter. By XOR'ing all characters in both strings, one additional character will be left out, since all others cancel each other out.

The C solution iterates over each character in both s and t, applying the XOR operation between them. Given XOR's properties, each pair of identical characters across s and t will cancel each other out, leaving the extra character as the result.