Permutation Difference between Two Strings(LeetCode 3146):

Problem

You are given two strings s and t such that every character occurs at most once in s and t is a permutation of s.

The permutation difference between s and t is defined as the sum of the absolute difference between the index of the occurrence of each character in s and the index of the occurrence of the same character in t.

Return the permutation difference between s and t.

 

Example 1:

Input: s = "abc", t = "bac"

Output: 2

Explanation:

For s = "abc" and t = "bac", the permutation difference of s and t is equal to the sum of:

  • The absolute difference between the index of the occurrence of "a" in s and the index of the occurrence of "a" in t.
  • The absolute difference between the index of the occurrence of "b" in s and the index of the occurrence of "b" in t.
  • The absolute difference between the index of the occurrence of "c" in s and the index of the occurrence of "c" in t.

That is, the permutation difference between s and t is equal to |0 - 1| + |2 - 2| + |1 - 0| = 2.

Example 2:

Input: s = "abcde", t = "edbac"

Output: 12

Explanation: The permutation difference between s and t is equal to |0 - 3| + |1 - 2| + |2 - 4| + |3 - 1| + |4 - 0| = 12.

 

Constraints:

  • 1 <= s.length <= 26
  • Each character occurs at most once in s.
  • t is a permutation of s.
  • s consists only of lowercase English letters.