Solve LeetCode #2558 using a priority queue.

LeetCode/src/LeetCode.Challenges/Problems25xx/N_2558_TakeGiftsFromTheRichestPile/MaxHeapSolution.cs

@@ -0,0 +1,29 @@
+namespace LeetCode.Challenges.Problems25xx.N_2558_TakeGiftsFromTheRichestPile;
+
+// Time Complexity: O(log n)
+public static class MaxHeapSolution
+{
+    public static long PickGifts(int[] gifts, int k)
+    {
+        PriorityQueue<int, int> maxHeap = new();
+        foreach (var gift in gifts)
+        {
+            maxHeap.Enqueue(gift, -gift);
+        }
+
+        for (var i = 0; i < k; i++)
+        {
+            var maxGift = maxHeap.Dequeue();
+            var remaining = (int)Math.Sqrt(maxGift);
+            maxHeap.Enqueue(remaining, -remaining);
+        }
+
+        var totalRemaining = 0L;
+        while (maxHeap.Count > 0)
+        {
+            totalRemaining += maxHeap.Dequeue();
+        }
+
+        return totalRemaining;
+    }
+}

LeetCode/tests/LeetCode.Challenges.UnitTests/Problems25xx/N_2558_TakeGiftsFromTheRichestPile/MaxHeapSolutionTests.cs

@@ -0,0 +1,15 @@
+using LeetCode.Challenges.Problems25xx.N_2558_TakeGiftsFromTheRichestPile;
+using Shouldly;
+using Xunit;
+
+namespace LeetCode.Challenges.UnitTests.Problems25xx.N_2558_TakeGiftsFromTheRichestPile;
+
+public class MaxHeapSolutionTests
+{
+    [Theory]
+    [ClassData(typeof(TestData))]
+    public void GivenGifts_WhenMinPickGifts_ThenResultAsExpected(int[] numbers, int k, long expectedResult)
+    {
+        MaxHeapSolution.PickGifts(numbers, k).ShouldBe(expectedResult);
+    }
+}