Merge k Sorted Arrays Java

PROGRAM TO MERGE K SORTED ARRAYS

import java.io.*;

import java.util.*;

 

class MAIN {

 

    // This function takes an array of arrays as an argument

    // and

    // All arrays are assumed to be sorted. It merges them

    // together and prints the final sorted output.

    public static void mergeKArrays(int[][] arr, int a,

                                    int[] output)

    {

        int c = 0;

 

        // traverse the matrix

        for (int i = 0; i < a; i++) {

            for (int j = 0; j < 4; j++)

                output[c++] = arr[i][j];

        }

 

        // sort the array

        Arrays.sort(output);

    }

 

    // A utility function to print array elements

    public static void printArray(int[] arr, int size)

    {

        for (int i = 0; i < size; i++)

            System.out.print(arr[i] + " ");

    }

   

    // Driver program to test above functions

    public static void main(String[] args)

    {

        int[][] arr = { { 2, 6, 12, 34 },

                        { 1, 9, 20, 1000 },

                        { 23, 34, 90, 2000 } };

        int k = 4;

        int n = 3;

        int[] output = new int[n * k];

 

        mergeKArrays(arr, n, output);

 

        System.out.println("Merged array is ");

        printArray(output, n * k);

    }

}




OUTPUT:

Merged array is 
1 2 6 9 12 20 23 34 34 90 1000 2000

CREDITS: https://www.geeksforgeeks.org/merge-k-sorted-arrays/