Java Program to Find k pairs with smallest sums in two arrays

// Java code to print first k pairs with least
// sum from two arrays.
import java.io.*;
 
class KSmallestPair
{
    // Function to find k pairs with least sum such
    // that one element of a pair is from arr1[] and
    // other element is from arr2[]
    static void kSmallestPair(int arr1[], int n1, int arr2[],
                                            int n2, int k)
    {
        if (k > n1*n2)
        {
            System.out.print("k pairs don't exist");
            return ;
        }
     
        // Stores current index in arr2[] for
        // every element of arr1[]. Initially
        // all values are considered 0.
        // Here current index is the index before
        // which all elements are considered as
        // part of output.
        int index2[] = new int[n1];
     
        while (k > 0)
        {
            // Initialize current pair sum as infinite
            int min_sum = Integer.MAX_VALUE;
            int min_index = 0;
     
            // To pick next pair, traverse for all 
            // elements of arr1[], for every element, find 
            // corresponding current element in arr2[] and
            // pick minimum of all formed pairs.
            for (int i1 = 0; i1 < n1; i1++)
            {
                // Check if current element of arr1[] plus
                // element of array2 to be used gives 
                // minimum sum
                if (index2[i1] < n2 && 
                    arr1[i1] + arr2[index2[i1]] < min_sum)
                {
                    // Update index that gives minimum
                    min_index = i1;
     
                    // update minimum sum
                    min_sum = arr1[i1] + arr2[index2[i1]];
                }
            }
     
            System.out.print("(" + arr1[min_index] + ", " +
                            arr2[index2[min_index]]+ ") ");
     
            index2[min_index]++;
            k--;
        }
    }

    // Driver code
    public static void main (String[] args)
    {
        int arr1[] = {1, 3, 11};
        int n1 = arr1.length;
     
        int arr2[] = {2, 4, 8};
        int n2 = arr2.length;
     
        int k = 4;
        kSmallestPair( arr1, n1, arr2, n2, k);
    }
}
/*This code is contributed by Prakriti Gupta*/