1974. Minimum Time to Type Word Using Special Typewriter: AC

Author: tan-wei

src/solution/mod.rs

@@ -1487,3 +1487,4 @@ mod s1968_array_with_elements_not_equal_to_average_of_neighbors;
 mod s1969_minimum_non_zero_product_of_the_array_elements;
 mod s1970_last_day_where_you_can_still_cross;
 mod s1971_find_if_path_exists_in_graph;
+mod s1974_minimum_time_to_type_word_using_special_typewriter;

src/solution/s1974_minimum_time_to_type_word_using_special_typewriter.rs

@@ -0,0 +1,113 @@
+/**
+ * [1974] Minimum Time to Type Word Using Special Typewriter
+ *
+ * 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'.
+ * <img alt="" src="https://assets.leetcode.com/uploads/2021/07/31/chart.jpg" style="width: 530px; height: 410px;" />
+ * Each second, you may perform one of the following operations:
+ *
+ * 	Move the pointer one character counterclockwise or clockwise.
+ * 	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.
+ *  
+ * Example 1:
+ *
+ * Input: word = "abc"
+ * Output: 5
+ * Explanation:
+ * The characters are printed as follows:
+ * - Type the character 'a' in 1 second since the pointer is initially on 'a'.
+ * - Move the pointer clockwise to 'b' in 1 second.
+ * - Type the character 'b' in 1 second.
+ * - Move the pointer clockwise to 'c' in 1 second.
+ * - Type the character 'c' in 1 second.
+ *
+ * Example 2:
+ *
+ * Input: word = "bza"
+ * Output: 7
+ * Explanation:
+ * The characters are printed as follows:
+ * - Move the pointer clockwise to 'b' in 1 second.
+ * - Type the character 'b' in 1 second.
+ * - Move the pointer counterclockwise to 'z' in 2 seconds.
+ * - Type the character 'z' in 1 second.
+ * - Move the pointer clockwise to 'a' in 1 second.
+ * - Type the character 'a' in 1 second.
+ *
+ * Example 3:
+ *
+ * Input: word = "zjpc"
+ * Output: 34
+ * Explanation:
+ * The characters are printed as follows:
+ * - Move the pointer counterclockwise to 'z' in 1 second.
+ * - Type the character 'z' in 1 second.
+ * - Move the pointer clockwise to 'j' in 10 seconds.
+ * - Type the character 'j' in 1 second.
+ * - Move the pointer clockwise to 'p' in 6 seconds.
+ * - Type the character 'p' in 1 second.
+ * - Move the pointer counterclockwise to 'c' in 13 seconds.
+ * - Type the character 'c' in 1 second.
+ *
+ *  
+ * Constraints:
+ *
+ * 	1 <= word.length <= 100
+ * 	word consists of lowercase English letters.
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/minimum-time-to-type-word-using-special-typewriter/
+// discuss: https://leetcode.com/problems/minimum-time-to-type-word-using-special-typewriter/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn min_time_to_type(word: String) -> i32 {
+        word.bytes()
+            .fold((word.len() as i32, b'a'), |(time, pointer), b| {
+                if pointer > b {
+                    (time + (pointer - b).min(26 + b - pointer) as i32, b)
+                } else {
+                    (time + (b - pointer).min(26 + pointer - b) as i32, b)
+                }
+            })
+            .0
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1974_example_1() {
+        let word = "abc".to_string();
+
+        let result = 5;
+
+        assert_eq!(Solution::min_time_to_type(word), result);
+    }
+
+    #[test]
+    fn test_1974_example_2() {
+        let word = "bza".to_string();
+
+        let result = 7;
+
+        assert_eq!(Solution::min_time_to_type(word), result);
+    }
+
+    #[test]
+    fn test_1974_example_3() {
+        let word = "zjpc".to_string();
+
+        let result = 34;
+
+        assert_eq!(Solution::min_time_to_type(word), result);
+    }
+}