389 Find the Difference

Bit Manipulation XOR 相同为0 不同为1

Given two stringssandtwhich consist of only lowercase letters.

Stringtis generated by random shuffling stringsand then add one more letter at a random position.

Find the letter that was added int.

Example:

Input:
s = "abcd"
t = "abcde"

Output:
e

Explanation:
'e' is the letter that was added.

time O(n)
space O(1)

class Solution {
    public char findTheDifference(String s, String t) {
        char c = t.charAt(t.length() - 1);
        for (int i = 0; i < s.length(); i++) {
            c ^= s.charAt(i);
            c ^= t.charAt(i);
        }
        return c;
    }
}