Add problem 2110: Number of Smooth Descent Periods of a Stock

src/lib.rs

@@ -1448,6 +1448,7 @@ pub mod problem_2099_find_subsequence_of_length_k_with_the_largest_sum;
 pub mod problem_2103_rings_and_rods;
 pub mod problem_2108_find_first_palindromic_string_in_the_array;
 pub mod problem_2109_adding_spaces_to_a_string;
+pub mod problem_2110_number_of_smooth_descent_periods_of_a_stock;
 pub mod problem_2114_maximum_number_of_words_found_in_sentences;
 pub mod problem_2119_a_number_after_a_double_reversal;
 pub mod problem_2124_check_if_all_as_appears_before_all_bs;

src/problem_2110_number_of_smooth_descent_periods_of_a_stock/iterative.rs

@@ -0,0 +1,40 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn get_descent_periods(prices: Vec<i32>) -> i64 {
+        let mut prev = 0;
+        let mut length = 0_u64;
+        let mut result = 0;
+
+        for price in prices {
+            if price + 1 == prev {
+                length += 1;
+            } else {
+                length = 1;
+            }
+
+            result += length;
+            prev = price;
+        }
+
+        result as _
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn get_descent_periods(prices: Vec<i32>) -> i64 {
+        Self::get_descent_periods(prices)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_2110_number_of_smooth_descent_periods_of_a_stock/mod.rs

@@ -0,0 +1,18 @@
+pub mod iterative;
+
+pub trait Solution {
+    fn get_descent_periods(prices: Vec<i32>) -> i64;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [(&[3, 2, 1, 4] as &[_], 7), (&[8, 6, 7, 7], 4), (&[1], 1)];
+
+        for (prices, expected) in test_cases {
+            assert_eq!(S::get_descent_periods(prices.to_vec()), expected);
+        }
+    }
+}