Package g2301_2400.s2351_first_letter_to_appear_twice

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    2351 - First Letter to Appear Twice.

    Easy

    Given a string s consisting of lowercase English letters, return the first letter to appear twice.

    Note:

    • A letter a appears twice before another letter b if the second occurrence of a is before the second occurrence of b.

    • s will contain at least one letter that appears twice.

    Example 1:

    Input: s = "abccbaacz"

    Output: "c"

    Explanation:

    The letter 'a' appears on the indexes 0, 5 and 6.

    The letter 'b' appears on the indexes 1 and 4.

    The letter 'c' appears on the indexes 2, 3 and 7.

    The letter 'z' appears on the index 8.

    The letter 'c' is the first letter to appear twice, because out of all the letters the index of its second occurrence is the smallest.

    Example 2:

    Input: s = "abcdd"

    Output: "d"

    Explanation:

    The only letter that appears twice is 'd' so we return 'd'.

    Constraints:

    • 2 <= s.length <= 100

    • s consists of lowercase English letters.

    • s has at least one repeated letter.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Character repeatedCharacter(String s)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait