Question

Write a method that takes 3 double arrays, merges all 3 arrays and returns a new array which stores all the values of the 3 arrays.

Please use Java and comment the code thank you

Answer 1

//Java program

public class ThreeMerge {
   public static void main(String args[]) {
       double arr1[] = {1,3};
       double arr2[] = {2,5};
       double arr3[] = {4,8};
      
       double arr[] = mergeThree(arr1,arr2,arr3);
      
       for(int i=0;i<arr.length;i++)
           System.out.print(arr[i]+" ");
   }
//function to merge three array
   private static double[] mergeThree(double[] arr1, double[] arr2, double[] arr3) {
       int l1=arr1.length;
       int l2 = arr2.length;
       int l3 = arr3.length;
       double A[] = new double[l1+l2];
       merge(arr1,arr2,A);
       double B[] = new double[l1+l2+l3];
       merge(arr3,A,B);
       return B;
   }
  
   //function to merge two array at a time into third array
   public static void merge(double [] A ,double B[],double C[]) {
  
   int first1= 0;
   int last1= A.length;
   int first2 = 0;
   int last2 = B.length;
   int index=0;
  
   while(first1<last1 && first2<last2) {
      
       if(A[first1]<B[first2]) {
           C[index] = A[first1];
           first1++;
       }
       else {
           C[index] = B[first2];
           first2++;
          
       }
       index++;
      
   }
   while(first1<last1) {
       C[index] = A[first1];
           first1++;
      
   }
   while(first2<last2) {
       C[index] = B[first2];
           first2++;
   }
  
}
}
//sample output