Question

Write a program in Java with a Scanner.

Given an array and a number k where k is smaller than the size of the array, write a program to find the k'th smallest element in the given array.

It is given that all array elements are distinct.

Example:

Input: arr[] = {7,10,4,3,20,15}

k = 3

Output: 7

Answer 1

import java.util.Arrays;
import java.util.Scanner;

public class KthSmallestElement {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);

        System.out.println("Enter all the numbers you want to put in array seperated by space: ");
        String line = in.nextLine();

        String tokens[] = line.split("\\s+");
        int arr[] = new int[tokens.length];
        for (int i = 0; i < arr.length; i++) {
            arr[i] = Integer.parseInt(tokens[i]);
        }

        System.out.print("Enter value of k: ");
        int k = in.nextInt();
        while(k < 1 || k > arr.length) {
            System.out.print("Invalid value.\nEnter value of k: ");
            k = in.nextInt();
        }

        // do k pass in
        for (int i = 0; i < k; i++) {
            // Last i elements are already in place
            for (int j = arr.length - 1; j > i; j--) {
                if (arr[j] < arr[j - 1]) {
                    int l = arr[j];
                    arr[j] = arr[j-1];
                    arr[j-1] = l;
                }
            }
        }

        //System.out.println(Arrays.toString(arr));

        System.out.println("Kth element of array: " + arr[k-1]);

        in.close();
    }

}