1964. Find the Longest Valid Obstacle Course at Each Position: RETRY

Author: tan-wei

Diff for: src/solution/mod.rs

@@ -1481,3 +1481,4 @@ mod s1960_maximum_product_of_the_length_of_two_palindromic_substrings;
 mod s1961_check_if_string_is_a_prefix_of_array;
 mod s1962_remove_stones_to_minimize_the_total;
 mod s1963_minimum_number_of_swaps_to_make_the_string_balanced;
+mod s1964_find_the_longest_valid_obstacle_course_at_each_position;

Diff for: src/solution/s1964_find_the_longest_valid_obstacle_course_at_each_position.rs

@@ -0,0 +1,110 @@
+/**
+ * [1964] Find the Longest Valid Obstacle Course at Each Position
+ *
+ * You want to build some obstacle courses. You are given a 0-indexed integer array obstacles of length n, where obstacles[i] describes the height of the i^th obstacle.
+ * For every index i between 0 and n - 1 (inclusive), find the length of the longest obstacle course in obstacles such that:
+ *
+ * 	You choose any number of obstacles between 0 and i inclusive.
+ * 	You must include the i^th obstacle in the course.
+ * 	You must put the chosen obstacles in the same order as they appear in obstacles.
+ * 	Every obstacle (except the first) is taller than or the same height as the obstacle immediately before it.
+ *
+ * Return an array ans of length n, where ans[i] is the length of the longest obstacle course for index i as described above.
+ *  
+ * Example 1:
+ *
+ * Input: obstacles = [1,2,3,2]
+ * Output: [1,2,3,3]
+ * Explanation: The longest valid obstacle course at each position is:
+ * - i = 0: [<u>1</u>], [1] has length 1.
+ * - i = 1: [<u>1</u>,<u>2</u>], [1,2] has length 2.
+ * - i = 2: [<u>1</u>,<u>2</u>,<u>3</u>], [1,2,3] has length 3.
+ * - i = 3: [<u>1</u>,<u>2</u>,3,<u>2</u>], [1,2,2] has length 3.
+ *
+ * Example 2:
+ *
+ * Input: obstacles = [2,2,1]
+ * Output: [1,2,1]
+ * Explanation: The longest valid obstacle course at each position is:
+ * - i = 0: [<u>2</u>], [2] has length 1.
+ * - i = 1: [<u>2</u>,<u>2</u>], [2,2] has length 2.
+ * - i = 2: [2,2,<u>1</u>], [1] has length 1.
+ *
+ * Example 3:
+ *
+ * Input: obstacles = [3,1,5,6,4,2]
+ * Output: [1,1,2,3,2,2]
+ * Explanation: The longest valid obstacle course at each position is:
+ * - i = 0: [<u>3</u>], [3] has length 1.
+ * - i = 1: [3,<u>1</u>], [1] has length 1.
+ * - i = 2: [<u>3</u>,1,<u>5</u>], [3,5] has length 2. [1,5] is also valid.
+ * - i = 3: [<u>3</u>,1,<u>5</u>,<u>6</u>], [3,5,6] has length 3. [1,5,6] is also valid.
+ * - i = 4: [<u>3</u>,1,5,6,<u>4</u>], [3,4] has length 2. [1,4] is also valid.
+ * - i = 5: [3,<u>1</u>,5,6,4,<u>2</u>], [1,2] has length 2.
+ *
+ *  
+ * Constraints:
+ *
+ * 	n == obstacles.length
+ * 	1 <= n <= 10^5
+ * 	1 <= obstacles[i] <= 10^7
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/find-the-longest-valid-obstacle-course-at-each-position/
+// discuss: https://leetcode.com/problems/find-the-longest-valid-obstacle-course-at-each-position/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn longest_obstacle_course_at_each_position(obstacles: Vec<i32>) -> Vec<i32> {
+        vec![]
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    #[ignore]
+    fn test_1964_example_1() {
+        let obstacles = vec![1, 2, 3, 2];
+
+        let result = vec![1, 2, 3, 3];
+
+        assert_eq!(
+            Solution::longest_obstacle_course_at_each_position(obstacles),
+            result
+        );
+    }
+
+    #[test]
+    #[ignore]
+    fn test_1964_example_2() {
+        let obstacles = vec![2, 2, 1];
+
+        let result = vec![1, 2, 1];
+
+        assert_eq!(
+            Solution::longest_obstacle_course_at_each_position(obstacles),
+            result
+        );
+    }
+
+    #[test]
+    #[ignore]
+    fn test_1964_example_3() {
+        let obstacles = vec![3, 1, 5, 6, 4, 2];
+
+        let result = vec![1, 1, 2, 3, 2, 2];
+
+        assert_eq!(
+            Solution::longest_obstacle_course_at_each_position(obstacles),
+            result
+        );
+    }
+}