Class Solution

java.lang.Object
g1301_1400.s1392_longest_happy_prefix.Solution

public class Solution extends java.lang.Object
1392 - Longest Happy Prefix.

Hard

A string is called a happy prefix if is a non-empty prefix which is also a suffix (excluding itself).

Given a string s, return the longest happy prefix of s. Return an empty string "" if no such prefix exists.

Example 1:

Input: s = “level”

Output: “l”

Explanation: s contains 4 prefix excluding itself (“l”, “le”, “lev”, “leve”), and suffix (“l”, “el”, “vel”, “evel”). The largest prefix which is also suffix is given by “l”.

Example 2:

Input: s = “ababab”

Output: “abab”

Explanation: “abab” is the largest prefix which is also suffix. They can overlap in the original string.

Constraints:

  • 1 <= s.length <= 105
  • s contains only lowercase English letters.
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    java.lang.String
    longestPrefix(java.lang.String s)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • longestPrefix

      public java.lang.String longestPrefix(java.lang.String s)