feat: add more

Author: gengjiawen

pools_todo/_2210_count_hills_and_valleys_in_an_array.rs renamed to Array/_2210_count_hills_and_valleys_in_an_array.rs

@@ -1,28 +1,28 @@
 // https://leetcode.com/problems/count-hills-and-valleys-in-an-array
-// 
+//
 // You are given a **0-indexed** integer array `nums`. An index `i` is part of a **hill** in `nums` if the closest non-equal neighbors of `i` are smaller than `nums[i]`. Similarly, an index `i` is part of a **valley** in `nums` if the closest non-equal neighbors of `i` are larger than `nums[i]`. Adjacent indices `i` and `j` are part of the **same** hill or valley if `nums[i] == nums[j]`.
-// 
+//
 // Note that for an index to be part of a hill or valley, it must have a non-equal neighbor on **both** the left and right of the index.
-// 
+//
 // Return _the number of hills and valleys in_ `nums`.
-// 
+//
 // **Example 1:**
-// 
+//
 // ```
 // **Input:** nums = [2,4,1,1,6,5]
 // **Output:** 3
 // **Explanation:**
 // At index 0: There is no non-equal neighbor of 2 on the left, so index 0 is neither a hill nor a valley.
-// At index 1: The closest non-equal neighbors of 4 are 2 and 1\. Since 4 > 2 and 4 > 1, index 1 is a hill. 
+// At index 1: The closest non-equal neighbors of 4 are 2 and 1\. Since 4 > 2 and 4 > 1, index 1 is a hill.
 // At index 2: The closest non-equal neighbors of 1 are 4 and 6\. Since 1 < 4 and 1 < 6, index 2 is a valley.
 // At index 3: The closest non-equal neighbors of 1 are 4 and 6\. Since 1 < 4 and 1 < 6, index 3 is a valley, but note that it is part of the same valley as index 2.
 // At index 4: The closest non-equal neighbors of 6 are 1 and 5\. Since 6 > 1 and 6 > 5, index 4 is a hill.
-// At index 5: There is no non-equal neighbor of 5 on the right, so index 5 is neither a hill nor a valley. 
+// At index 5: There is no non-equal neighbor of 5 on the right, so index 5 is neither a hill nor a valley.
 // There are 3 hills and valleys so we return 3.
 // ```
-// 
+//
 // **Example 2:**
-// 
+//
 // ```
 // **Input:** nums = [6,6,5,5,4,1]
 // **Output:** 0
@@ -35,16 +35,34 @@
 // At index 5: There is no non-equal neighbor of 1 on the right, so index 5 is neither a hill nor a valley.
 // There are 0 hills and valleys so we return 0.
 // ```
-// 
+//
 // **Constraints:**
-// 
+//
 // *   `3 <= nums.length <= 100`
 // *   `1 <= nums[i] <= 100`
 
 pub fn count_hill_valley(nums: Vec<i32>) -> i32 {
+    let mut res = 0;
+    let mut new_num = Vec::new();
+    new_num.push(nums[0]);
+    for i in 1..nums.len() {
+        if nums[i] != nums[i - 1] {
+            new_num.push(nums[i]);
+        }
+    }
 
+    for i in 1..new_num.len() - 1 {
+        if new_num[i] > new_num[i - 1] && new_num[i] > new_num[i + 1] {
+            res += 1;
+        }
+        if new_num[i] < new_num[i - 1] && new_num[i] < new_num[i + 1] {
+            res += 1;
+        }
     }
+    return res;
+}
 
 #[test]
 pub fn t1() {
+    assert_eq!(count_hill_valley(vec![2, 4, 1, 1, 6, 5]), 3);
 }

Array/lib.rs

@@ -157,6 +157,7 @@ mod _2164_sort_even_and_odd_indices_independently;
 mod _2176_count_equal_and_divisible_pairs_in_an_array;
 mod _2185_counting_words_with_a_given_prefix;
 mod _2206_divide_array_into_equal_pairs;
+mod _2210_count_hills_and_valleys_in_an_array;
 mod _2215_find_the_difference_of_two_arrays;
 mod _2229_check_if_an_array_is_consecutive;
 mod _2235_add_two_integers;