Commit 8d40d24

@@ -0,0 +1,55 @@
+<<-DOC
+Find the kth largest element in an unsorted array. This will be the kth largest element in sorted order, not the kth distinct element.
+
+Example
+
+For nums = [7, 6, 5, 4, 3, 2, 1] and k = 2, the output should be
+kthLargestElement(nums, k) = 6;
+For nums = [99, 99] and k = 1, the output should be
+kthLargestElement(nums, k) = 99.
+Input/Output
+
+[time limit] 4000ms (rb)
+[input] array.integer nums
+
+Guaranteed constraints:
+1 ≤ nums.length ≤ 105,
+-105 ≤ nums[i] ≤ 105.
+
+[input] integer k
+
+Guaranteed constraints:
+1 ≤ k ≤ nums.length.
+
+[output] integer
+DOC
+
+describe "#kth_largest_element" do
+  def kth_largest_element(numbers, k)
+    numbers.sort[-k]
+  end
+
+  [
+    { nums: [7, 6, 5, 4, 3, 2, 1], k: 2, x: 6 },
+    { nums: [99, 99], k: 1, x: 99 },
+    { nums: [1], k: 1, x: 1 },
+    { nums: [2, 1], k: 1, x: 2 },
+    { nums: [-1, 2, 0], k: 2, x: 0 },
+    { nums: [-1, 2, 0], k: 3, x: -1 },
+    { nums: [3, 1, 2, 4], k: 2, x: 3 },
+    { nums: [3, 2, 1, 5, 6, 4], k: 2, x: 5 },
+    { nums: [5, 2, 4, 1, 3, 6, 0], k: 2, x: 5 },
+    { nums: [3, 3, 3, 3, 3, 3, 3, 3, 3], k: 8, x: 3 },
+    { nums: [3, 3, 3, 3, 4, 3, 3, 3, 3], k: 1, x: 4 },
+    { nums: [3, 3, 3, 3, 4, 3, 3, 3, 3], k: 5, x: 3 },
+    { nums: [3, 2, 3, 1, 2, 4, 5, 5, 6], k: 4, x: 4 },
+    { nums: [3, 2, 3, 1, 2, 4, 5, 5, 6, 7, 7, 8, 2, 3, 1, 1, 1, 10, 11, 5, 6, 2, 4, 7, 8, 5, 6], k: 1, x: 11 },
+    { nums: [2, 1], k: 2, x: 1 },
+    { nums: [-1, -1], k: 2, x: -1 },
+  ].each do |x|
+    it do
+      expect(kth_largest_element(x[:nums], x[:k])).to eql(x[:x])
+    end
+  end
+
+end