Demonstration of Merging K-Sorted Array With Unique Elements

MergeDemo.java

package com.levo.odev;

/*
 * En buyuk Fenerbahce!
 */
public class MergeDemo {

	public static void main(String[] args) {
		int[] arr1 = { 1, 2, 6, 7, 18, 19 };
		int[] arr2 = { 3, 4, 5, 8, 9 };
		int[] arr3 = { 10, 11, 12 };
		int[] arr4 = { 13, 14, 15, 20};
		int[] arr5 = { 16, 17};
		
		int[][] arrays = { arr1, arr2, arr3, arr4, arr5 };
		
		handleAnswer(arrays);
	}
	
	public static void handleAnswer(int[][] arrays) {
		System.out.println("List of arrays to be merged;");
		System.out.println("****************************");
		for(int i = 0; i < arrays.length; i++) {
			System.out.printf("Array [%d]: ", i);
			printArray(arrays[i]);
		}
		
		System.out.println("");
		System.out.println("Merged array;");
		System.out.println("*************");
		printArray(merge(arrays));
	}
	
	public static void printArray(int[] array) {
		for(int i = 0; i < array.length; i++)
			System.out.printf("%d ", array[i]);
		System.out.print('\n');
	}
	
	/*
	 * Merges k sorted arrays with arbitrary lengths
	 * Calls overloaded merge method with two parameters
	 */
	private static int[] merge(int[][] arrays) {
		int[] mergeArray = new int[arrays[0].length];
		System.arraycopy(arrays[0], 0, mergeArray, 0, arrays[0].length);
		
		for(int i = 1; i < arrays.length; i++) {
			mergeArray = merge(mergeArray, arrays[i]);
		}
		
		return mergeArray;
	}
	
	/*
	 * Merges two sorted arrays assuming 
	 * they have unique elements
	 */
	private static int[] merge(int[] arr1, int[] arr2) {
		int left = 0;
		int right = 0;
		
		int[] mergeArr = new int[ arr1.length + arr2.length ];
		int index = 0;
		
		while(index != mergeArr.length){
			if(left == arr1.length) {
				while(right != arr2.length) {
					mergeArr[index++] = arr2[right++];
				}
			} else if(right == arr2.length) {
				while(left != arr1.length) {
					mergeArr[index++] = arr1[left++];
				}
			} else {
				if(arr1[left] < arr2[right]) {
					mergeArr[index++] = arr1[left++];
				} else {
					mergeArr[index++] = arr2[right++];
				}
			}
		}

		return mergeArr;
	}
}

Output;

[List of arrays to be merged;
****************************
Array [0]: 1 2 6 7 18 19 
Array [1]: 3 4 5 8 9 
Array [2]: 10 11 12 
Array [3]: 13 14 15 20 
Array [4]: 16 17 

Merged array;
*************
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20