README_EN.md

1165. Single-Row Keyboard

中文文档

Description

There is a special keyboard with all keys in a single row.

Given a string keyboard of length 26 indicating the layout of the keyboard (indexed from 0 to 25). 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 |i - j|.

You want to type a string word. Write a function to calculate how much time it takes to type it with one finger.

 

Example 1:

Input: keyboard = "abcdefghijklmnopqrstuvwxyz", word = "cba"
Output: 4
Explanation: The index moves from 0 to 2 to write 'c' then to 1 to write 'b' then to 0 again to write 'a'.
Total time = 2 + 1 + 1 = 4. 

Example 2:

Input: keyboard = "pqrstuvwxyzabcdefghijklmno", word = "leetcode"
Output: 73

 

Constraints:

• keyboard.length == 26
• keyboard contains each English lowercase letter exactly once in some order.
• 1 <= word.length <= 104
• word[i] is an English lowercase letter.

Solutions

Python3

class Solution:
    def calculateTime(self, keyboard: str, word: str) -> int:
        index = {c: i for i, c in enumerate(keyboard)}
        res = t = 0
        for c in word:
            res += abs(index[c] - t)
            t = index[c]
        return res

Java

class Solution {
    public int calculateTime(String keyboard, String word) {
        Map<Character, Integer> index = new HashMap<>();
        for (int i = 0; i < keyboard.length(); ++i) {
            index.put(keyboard.charAt(i), i);
        }
        int res = 0, t = 0;
        for (char c : word.toCharArray()) {
            res += Math.abs(index.get(c) - t);
            t = index.get(c);
        }
        return res;
    }
}

C++

class Solution {
public:
    int calculateTime(string keyboard, string word) {
        unordered_map<char, int> index;
        for (int i = 0; i < keyboard.size(); ++i) {
            index[keyboard[i]] = i;
        }
        int res = 0, t = 0;
        for (char c : word) {
            res += abs(index[c] - t);
            t = index[c];
        }
        return res;
    }
};

Go

func calculateTime(keyboard string, word string) int {
	index := map[byte]int{}
	for i := 0; i < len(keyboard); i++ {
		index[keyboard[i]] = i
	}
	res := 0
	t := 0
	for i := 0; i < len(word); i++ {
		res += abs(index[word[i]] - t)
		t = index[word[i]]
	}
	return res
}

func abs(x int) int {
	if x < 0 {
		return -x
	}
	return x
}

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