Add problem 3194: Minimum Average of Smallest and Largest Elements

Author: EFanZh

src/lib.rs

@@ -2130,6 +2130,7 @@ pub mod problem_3186_maximum_total_damage_with_spell_casting;
 pub mod problem_3190_find_minimum_operations_to_make_all_elements_divisible_by_three;
 pub mod problem_3191_minimum_operations_to_make_binary_array_elements_equal_to_one_i;
 pub mod problem_3192_minimum_operations_to_make_binary_array_elements_equal_to_one_ii;
+pub mod problem_3194_minimum_average_of_smallest_and_largest_elements;
 pub mod problem_3350_adjacent_increasing_subarrays_detection_ii;
 
 #[cfg(test)]

src/problem_3194_minimum_average_of_smallest_and_largest_elements/iterative.rs

@@ -0,0 +1,35 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn minimum_average(nums: Vec<i32>) -> f64 {
+        let mut nums = nums.into_iter().map(i32::cast_unsigned).collect::<Vec<_>>();
+
+        nums.sort_unstable();
+
+        let (left, right) = nums.split_at(nums.len() / 2);
+
+        f64::from(
+            left.iter()
+                .zip(right.iter().rev())
+                .fold(u32::MAX, |min, (&x, &y)| min.min(x + y)),
+        ) / 2.0
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn minimum_average(nums: Vec<i32>) -> f64 {
+        Self::minimum_average(nums)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_3194_minimum_average_of_smallest_and_largest_elements/mod.rs

@@ -0,0 +1,22 @@
+pub mod iterative;
+
+pub trait Solution {
+    fn minimum_average(nums: Vec<i32>) -> f64;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            (&[7, 8, 3, 4, 15, 13, 4, 1] as &[_], 5.5),
+            (&[1, 9, 8, 3, 10, 5], 5.5),
+            (&[1, 2, 3, 7, 8, 9], 5.0),
+        ];
+
+        for (nums, expected) in test_cases {
+            approx::assert_ulps_eq!(S::minimum_average(nums.to_vec()), expected);
+        }
+    }
+}