Rearrange Characters to Make Target String

The problem can be approached by counting the occurrences of each character in both strings s and target. The maximum number of copies of target that can be formed from s will be the minimum count of a character in s divided by the count of that character in target, for each character in target.

Here is a step-by-step thought process:

  1. First, create two dictionaries (or hash maps), s_count and target_count, to store the counts of each character in s and target respectively.

  2. Iterate through each character in s, incrementing the corresponding count in s_count.

  3. Do the same for target, incrementing counts in target_count.

  4. Initialize a variable max_copies to a large value. This variable will store the maximum number of copies of target that can be formed.

  5. For each character in target_count, compute the number of copies that can be formed using the character counts from s and target. This is done by dividing the count of the character in s_count by its count in target_count.

  6. If this number is less than max_copies, update max_copies to this value.

  7. Return max_copies as the maximum number of copies of target that can be formed from s.

Python code:

class Solution:
    def rearrangeCharacters(self, s: str, target: str) -> int:
        from collections import Counter

        s_count = Counter(s)
        target_count = Counter(target)

        max_copies = float('inf')

        for char in target_count:
            if char in s_count:
                max_copies = min(max_copies, s_count[char] // target_count[char])
                return 0

        return max_copies

In this code, the Counter object from the collections module is used to count the occurrences of characters in the strings s and target. We iterate over each character in target_count, checking if it exists in s_count. If it does, we calculate the number of copies that can be made from that character and update max_copies if it’s less than the current max_copies. If a character from target is not present in s, we return 0 since we can’t form any copy of target without this character. The function finally returns the max_copies as the solution.