Description
Solutions
Submission
Minimum Steps Required

Given two strings str1 and str2 containing only 0s and 1s, there are steps to change str1 to str2:

  • Find a substring of str1 of length 2 and reverse it, resulting in str1' (where str1' != str1).
  • Find a substring of str1' of length 3, reverse it, resulting in str1'' (where str1'' != str1').
  • Repeat similar steps.

    • String length ranges from 2 to 30.

    Requirements: 🤩

  • Each step must be performed once, and you cannot skip previous steps to perform the next step.
  • If it's possible to change str1 to str2, output the minimum required steps. Otherwise, output -1.

    • Example 1: 

    Input:  str1 = "1010", str2 = "0011"
    Output: 2 
    Explanation:
    
Steps:


  • Choose substring in range [2, 3]: "1010" → "1001"
    • 


  • Choose substring in the range [0, 2]: "1001" → "0011"
    •

    Example 2: 

    Input:  str1 = "1001", str2 = "0110"
    Output: -1 
    Explanation:
    
It's impossible to change str1 to str2.

    Example 3: 

    Input:  str1 = "10101010", str2 = "00101011"
    Output: 7 
    Explanation:
    
The minimum steps required to change str1 to str2 is 7.
    Constraints:
      N/A
    Thumbnail 0
    Testcase
    Result
    Case 1

    input:

    output: