Description
Given two strings s*** and **t* which consist of only lowercase letters.
String t*** is generated by random shuffling string **s* and then add one more letter at a random position.
Find the letter that was added in *t*.
Example:
Input:
s = "abcd"
t = "abcde"
Output:
e
Explanation:
'e' is the letter that was added.
Solutions
1. Bit manipulation
# Time: O(n)
# Space: O(1)
class Solution:
def findTheDifference(self, s: str, t: str) -> str:
code = 0
for ch in s + t:
code ^= ord(ch)
return chr(code)
# Runtime: 32 ms, faster than 65.80%
# Memory Usage: 12.8 MB, less than 100.00%