Add problem 2517: Maximum Tastiness of Candy Basket

Author: EFanZh

src/lib.rs

@@ -1877,6 +1877,7 @@ pub mod problem_2511_maximum_enemy_forts_that_can_be_captured;
 pub mod problem_2512_reward_top_k_students;
 pub mod problem_2515_shortest_distance_to_target_string_in_a_circular_array;
 pub mod problem_2516_take_k_of_each_character_from_left_and_right;
+pub mod problem_2517_maximum_tastiness_of_candy_basket;
 
 #[cfg(test)]
 mod test_utilities;

src/problem_2517_maximum_tastiness_of_candy_basket/binary_search.rs

@@ -0,0 +1,62 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+use std::iter::Copied;
+use std::slice::Iter;
+
+impl Solution {
+    fn check(first_price: u32, mut price_iter: Copied<Iter<u32>>, k: u32, candidate: u32) -> bool {
+        let mut prev = first_price;
+
+        (1..k).all(|_| {
+            let target = prev + candidate;
+
+            price_iter.find(|&value| value >= target).is_some_and(|next| {
+                prev = next;
+
+                true
+            })
+        })
+    }
+
+    pub fn maximum_tastiness(price: Vec<i32>, k: i32) -> i32 {
+        let mut price = price.into_iter().map(|x| x as u32).collect::<Vec<_>>();
+        let k = k as u32;
+
+        price.sort_unstable();
+
+        let mut iter = price.iter().copied();
+        let first_price = iter.next().unwrap();
+        let mut left = 0;
+        let mut right = (price.last().unwrap() - first_price) / (k - 1) + 1;
+
+        while left < right {
+            let middle = (left + right) / 2;
+
+            if Self::check(first_price, iter.clone(), k, middle) {
+                left = middle + 1;
+            } else {
+                right = middle;
+            }
+        }
+
+        (left - 1) as _
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn maximum_tastiness(price: Vec<i32>, k: i32) -> i32 {
+        Self::maximum_tastiness(price, k)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_2517_maximum_tastiness_of_candy_basket/mod.rs

@@ -0,0 +1,22 @@
+pub mod binary_search;
+
+pub trait Solution {
+    fn maximum_tastiness(price: Vec<i32>, k: i32) -> i32;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            ((&[13, 5, 1, 8, 21, 2] as &[_], 3), 8),
+            ((&[1, 3, 1], 2), 2),
+            ((&[7, 7, 7, 7], 2), 0),
+        ];
+
+        for ((price, k), expected) in test_cases {
+            assert_eq!(S::maximum_tastiness(price.to_vec(), k), expected);
+        }
+    }
+}