ThirdSmallestNumber.java

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

/**
*   Program:    ThirdSmallestNumber.java
*   Purpose:    Display 3rd smallest number in an array
*   Creator:    Chris Clarke, author "50 Java Program Source Codes"
*   Created:    04.06.2014
*/

public class ThirdSmallestNumber {

    static final int MAX = 10;

    static int[] k = new int[MAX];

    public static void main(String[] args) {

        // create scanner object to read user input by keyboard
        Scanner in = new Scanner(System.in);

        // prompt for user input
        System.out.println("Enter 10 numbers:");

        // loop MAX times
        for( int i =0; i<MAX; i++) {
            // get user input
            k[i] = in.nextInt();
        } // end for

        // display result
        System.out.println("The 3rd smallest number is: "+getThirdSmallest( k));
    } // end main()


    // find 3rd smallest number in array
    public static int getThirdSmallest(int[] k) {
     // works with or without repeated numbers
     // e.g. k = {1, 1, 1, 2, 2, 3, ...} returns 3, not 1

        // sort array in ascending numerical order
        Arrays.sort(k);

        // display sorted array
        //System.out.println( Arrays.toString( k));

        // k[0] is smallest
        int i=0;

        // find second- & third- smallest numbers
        // (not as simple as returning k[2] - see example above)

        // loop twice
        for (int j=2; j<=3; j++) {
            // iterate through any repeated numbers
            while (i<k.length-1 && k[i] == k[i+1]) i++;

            // move on to next different index, if it exists
            if (i<k.length-1) i++;
        } // end for j

        // returns number at position i of array k
        return k[i];

    } // end getThirdSmallest()

} // end class ThirdSmallestNumber