Create Kth Smallest Element.java

Author: py3-coder

Heap/Kth Smallest Element.java

@@ -0,0 +1,51 @@
+// Heap Questions:::
+//Problem Statement :: Kth Smallest Element in given array.
+// IP : arr[] =7 10 4 3 20 15 ,k=3
+// OP : 7
+
+/*
+Broute Force :: Array Sort:
+TC : O(nlogn)
+SC : O(1)
+
+Optimal Approch:: Heap Method::
+TC : O(nlogk)
+SC : O(k)
+
+*/
+import java.util.*;
+public class Main
+{
+	public static void main(String[] args) {
+	    int arr[] = new int[]{6,10,4,3,20,15,21,18,2};
+	    int k=5;
+	    int val =kthSmallestele(arr,k);
+		System.out.println(k+"th Smallest ::"+val);
+		 val =kthSmallestele(arr,7);
+		System.out.println("7th Smallest ::"+val);
+		 val =kthSmallestele(arr,3);
+		System.out.println("3rd Smallest ::"+val);
+		 val =kthSmallestele(arr,8);
+		System.out.println("8th Smallest ::"+val);
+		//Lets Check :: 2,3,4,6,10,15,18,20,21
+	}
+	public static int kthSmallestele(int[] arr,int k){
+	    //Smallest given:: so we will make Max heap::
+	    PriorityQueue<Integer> maxheap = new PriorityQueue<>((a,b)->b-a);
+	    for(int i=0;i<arr.length;i++){
+	        maxheap.add(arr[i]);
+	        if(maxheap.size()>k){
+	            maxheap.poll();
+	        }
+	    }
+	    return maxheap.peek();
+	}
+}
+
+/*
+OutPut ::
+5th Smallest ::10
+7th Smallest ::18
+3rd Smallest ::4
+8th Smallest ::20
+*/