kth largest element in unsorted array LC215

ArraysAndStrings/Tutorial.md

@@ -260,4 +260,6 @@ void printTwoSum(int[] array, int k)
             }
         }
     }
-```
+```
+
+**[Kth Largest in an array](https://github.com/ankurjuneja/React-Java-Concepts/blob/master/src/ArraysAndStrings/Kthlargest.java)**

src/ArraysAndStrings/Kthlargest.java

@@ -0,0 +1,57 @@
+package ArraysAndStrings;
+
+public class Kthlargest
+{
+    public static int findKthLargest(int[] nums, int k)
+    {
+       if (null == nums || nums.length == 0)
+       {
+           return Integer.MIN_VALUE;
+       }
+
+       return qSort(nums, 0, nums.length-1, k);
+    }
+
+    private static int qSort(int[] nums, int left, int right, int k)
+    {
+        if (nums[left] >= nums[right])
+        {
+            return nums[right];
+        }
+
+        int i = left;
+        for (int j = left + 1; j <=  right; j++)
+        {
+            if (nums[j] > nums[i]) {
+                i++;
+                swap(nums, i, j);
+            }
+        }
+            swap(nums, i, left);
+
+            if (k == i + 1)
+            {
+                return nums[i];
+            }
+            else if (k > i + 1)
+            {
+                return qSort(nums, i+1, right, k);
+            }
+            else
+            {
+                return qSort(nums, left, i-1, k);
+            }
+    }
+
+    private static void swap(int[] nums, int i, int j)
+    {
+        int tmp = nums[i];
+        nums[i] = nums[j];
+        nums[j] = tmp;
+    }
+
+    public static void main(String[] args)
+    {
+        int  secondlargest = findKthLargest(new int[]{3,2,5,1,6,4}, 2);
+    }
+}