Given a string s and a string t, find the minimum window in s that contains all the characters of t in any order. If there is no such window, return an empty string “”.

If there is repetitive character in t, the returned window should contain at least the same number of that character.

The window should be of a minimum length, and you are required to find this minimum length.

Function Signature:

def min_window_substring(s: str, t: str) -> str:
    """
    Find the minimum window in s that contains all characters of t.

    Parameters:
    - s: A string where the minimum window should be found.
    - t: A string representing the characters to be included in the minimum window.

    Returns:
    - str: The minimum window substring or an empty string if not found.
    """
    # Your code here

Example:

result = min_window_substring("ab", "a")
print(result)
assert result == "a"
# Explanation: The minimum window substring "a" contains the character "a".

result = min_window_substring("abccb", "cc")
print(result)
assert result == "cc"
# Explanation: The minimum window substring "cc" contains the characters of "cc" (two c's).

result = min_window_substring("ADOBXBCODEBANC", "ABC")
print(result)
assert result == "BANC"
# Explanation: The minimum window substring "BANC" contains all characters of "ABC".

result = min_window_substring("x", "a")
print(result)
assert result == ""
# Explanation: There is no window containing "a" in the string "x".

result = min_window_substring("a", "aa")
print(result)
assert result == ""
# Explanation: There is no window containing "aa" (two a's) in the string "a".

Note:

  • The characters in the strings are case-sensitive.
  • The order of characters in the minimum window does not matter.
  • If there are multiple valid answers, return any valid window.
  • Both s and t are non-empty.

Instructions:

  • Write the min_window_substring function to solve the problem.
  • Implement your solution in Python.
  • Provide clear comments in your code.
  • Discuss the time and space complexity of your solution.

As always, we’ll share our solution to this problem tomorrow. Stay tuned 😊