Find_the_Difference.py

# 389. Find the Difference

# You are given two strings s and t.

# String t is generated by random shuffling string s and then add one more letter at a random position.

# Return the letter that was added to t.

 

# Example 1:

# Input: s = "abcd", t = "abcde"
# Output: "e"
# Explanation: 'e' is the letter that was added.
# Example 2:

# Input: s = "", t = "y"
# Output: "y"
 

# Constraints:

# 0 <= s.length <= 1000
# t.length == s.length + 1
# s and t consist of lowercase English letters.

# solution
class Solution:
  def findTheDifference(self, s: str, t: str) -> str:
    count = collections.Counter(s)

    for i, c in enumerate(t):
      count[c] -= 1
      if count[c] == -1:
        return c