Chef's Ingredient Rearrangement — Problem Statement & Solution Guide
Problem Description
Given two strings of ingredients, s1 and s2, of the same length, determine the minimum number of swap operations on the characters of s1 to transform it into s2.
Examples
Input
s1 = 'ab', s2 = 'ba'
Output
1
Explanation: Step-by-step: We need to swap 'a' and 'b' in s1 to get s2. This requires 1 operation.
Input
s1 = 'xyz', s2 = 'zyx'
Output
2
Explanation: Step-by-step: We can swap 'x' and 'z' first, then 'y' and 'z' to get s2. This requires 2 operations.
Constraints
- 1 <= length of s1 == length of s2 <= 100
- s1 and s2 contain only lowercase English letters
- The input strings can be modified, and additional space can be used for bookkeeping
Optimal Approach & Strategy
An optimized approach is to use a cycle detection algorithm to find the minimum number of swap operations, resulting in a time complexity of O(n).
Brute Force Approach
One possible brute-force approach is to generate all permutations of the first string and count the minimum number of swaps required to transform it into the second string, resulting in a time complexity of O(n!).
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