Statement
Solution
Naive approach
The naive approach would be to find all possible substrings of s
and then identify the shortest substring that contains all characters of t
with corresponding frequencies equal to or greater than those in t
.
To find all possible substrings, we will iterate over s
one character at a time. For each character, we will form all possible substrings starting from that character.
We will keep track of the frequencies of the characters in the current substring. If the frequencies of the characters of t
in the substring are equal to or greater than their overall frequencies in t
, save the substring given that the length of this substring is less than the one already saved. After traversing s
, return the minimum window substring.
The time complexity of this approach will be , where is the length of s
. The space complexity of this approach will be , the space used in memory to track the frequencies of the characters of the current substring.