Package g0001_0100.s0087_scramble_string

Class Solution

java.lang.Object
g0001_0100.s0087_scramble_string.Solution
public class Solution extends java.lang.Object
87 - Scramble String.

Hard

We can scramble a string s to get a string t using the following algorithm:

  1. If the length of the string is 1, stop.
  2. If the length of the string is > 1, do the following:
    • Split the string into two non-empty substrings at a random index, i.e., if the string is s, divide it to x and y where s = x + y.
    • Randomly decide to swap the two substrings or to keep them in the same order. i.e., after this step, s may become s = x + y or s = y + x.
    • Apply step 1 recursively on each of the two substrings x and y.

Given two strings s1 and s2 of the same length , return true if s2 is a scrambled string of s1, otherwise, return false.

Example 1:

Input: s1 = “great”, s2 = “rgeat”

Output: true

Explanation: One possible scenario applied on s1 is: “great” –> “gr/eat” // divide at random index. “gr/eat” –> “gr/eat” // random decision is not to swap the two substrings and keep them in order. “gr/eat” –> “g/r / e/at” // apply the same algorithm recursively on both substrings. divide at ranom index each of them. “g/r / e/at” –> “r/g / e/at” // random decision was to swap the first substring and to keep the second substring in the same order. “r/g / e/at” –> “r/g / e/ a/t” // again apply the algorithm recursively, divide “at” to “a/t”. “r/g / e/ a/t” –> “r/g / e/ a/t” // random decision is to keep both substrings in the same order. The algorithm stops now and the result string is “rgeat” which is s2. As there is one possible scenario that led s1 to be scrambled to s2, we return true.

Example 2:

Input: s1 = “abcde”, s2 = “caebd”

Output: false

Example 3:

Input: s1 = “a”, s2 = “a”

Output: true

Constraints:

  • s1.length == s2.length
  • 1 <= s1.length <= 30
  • s1 and s2 consist of lower-case English letters.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    isScramble(java.lang.String s1, java.lang.String s2)
     

    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

    • isScramble

      public boolean isScramble(java.lang.String s1, java.lang.String s2)