Leetcode 1165 Single-Row Keyboard

Problem statement

https://leetcode.com/problems/single-row-keyboard/

Solution

First, collect all places for all letters in keyboard. Then iterate through word and add absolute difference to answer. Also we need to deal with first letter, for this I add keyboard[0] to the start of word.

Complexity

Time complexity is O(26 + n), space complexity is O(26).

Code

class Solution:
    def calculateTime(self, keyboard, word):
        places = {s: i for i, s in enumerate(keyboard)}
        ans = 0
        for x, y in zip(word, keyboard[0] + word):
            ans += abs(places[x] - places[y])
            
        return ans