LeetCode 1165. Single-Row Keyboard

Problem Statement

use std::collections::HashMap;

impl Solution {
    pub fn calculate_time(keyboard: String, word: String) -> i32 {
        let mut map = HashMap::new();
        for i in 0..26 {
            map.insert(keyboard.chars().nth(i).unwrap(), i);
        }

        let (mut ans, size) = (0, word.len());
        if size == 1 {
            return ans;
        }
        
        for i in 0..size {
            let ci = word.chars().nth(i).unwrap();
            if i == 0 {
                ans += *map.get(&ci).unwrap() as i32;
                continue;
            }
            let cii = word.chars().nth(i - 1).unwrap();
            ans += (*map.get(&cii).unwrap() as i32
                - *map.get(&ci).unwrap() as i32).abs();
        }
        return ans;
    }
}