1165. Single-Row Keyboard 单行键盘

@TOC

# 题目描述

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:

1. `keyboard.length == 26`
2. keyboard contains each English lowercase letter exactly once in some order.
3. `1 <= word.length <= 10^4`
4. `word[i]` is an English lowercase letter.

# 解题方法

# 字典

C++代码如下：

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

# 日期

2019 年 9 月 18 日 —— 今日又是九一八