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.

Pre analysis

Will just follow the algorithm and check the difference between the index of the occurrence of each character in s and the index of the occurrence of the same character in t.