Problem Description
There is a special typewriter with lowercase English letters 'a' to 'z' arranged in a circle with a pointer. A character can only be typed if the pointer is pointing to that character. The pointer is initially pointing to the character 'a'. Each second, you may perform one of the following operations: move the pointer one character counterclockwise or clockwise, or type the character the pointer is currently on. Given a string word, return the minimum number of seconds to type out the characters in word.
Key Insights
- The typewriter operates on a circular arrangement of the alphabet.
- Moving the pointer can be done either counterclockwise or clockwise, and we should choose the shorter distance for efficiency.
- Each character typing takes 1 second, so we must account for both move time and type time.
Space and Time Complexity
Time Complexity: O(n), where n is the length of the word. Space Complexity: O(1), as we're using a constant amount of space for calculations.
Solution
To solve this problem, we can iterate through each character in the string and calculate the time needed to move the pointer from the current character to the next character. We can compute the distance in both directions (clockwise and counterclockwise) and take the minimum of the two. After calculating the move time, we add 1 second for typing the character. We'll maintain a total time counter that accumulates the seconds spent on both movements and typings.