https://leetcode.com/problems/single-row-keyboard (premium)

Imagine you have a special keyboard with all keys in a single row. The layout of characters on a keyboard is denoted by a string keyboard of length 26. Initially your finger is at index 0. To type a character, you have to move your finger to the index of the desired character. The time taken to move your finger from index i to index j is abs(j - i).

Given a string keyboard that describe the keyboard layout and a string text, return an integer denoting the time taken to type string text.

Example 1:

Input: keyboard = "abcdefghijklmnopqrstuvwxy", text = "cba" 
Output: 4
Explanation:
Initially your finger is at index 0. First you have to type 'c'. The time taken to type 'c' will be abs(2 - 0) = 2 because character 'c' is at index 2.
The second character is 'b' and your finger is now at index 2. The time taken to type 'b' will be abs(1 - 2) = 1 because character 'b' is at index 1.
The third character is 'a' and your finger is now at index 1. The time taken to type 'a' will be abs(0 - 1) = 1 because character 'a' is at index 0.
The total time will therefore be 2 + 1 + 1 = 4.

Constraints:

• length of keyboard will be equal to 26 and all the lowercase letters will occur exactly once;
• the length of text is within the range [1..100,000];
• string text contains only lowercase letters [a-z].