CareerCup

i=j=k=0;
while (i <= a.length && j <= b.length)
{
if a[i] < b[j];
{
final[k] = a[i];
i++;
}
else
{
final[k] = b[j];
j++;
}
k++
}

while (i <= a.length)
{
final[k]=a[i];
i++
k++
}

while (j< = b.length)
{
final[k]= b[j];
j++;
k++;
}

same as merge sort last step which is combine.

I found the solution in the book titled "Elements of Programming Interviews".

The solution is a special case of "Merging sorted files" problem in that book. You can Google and find their solutions in C++ at Google Code.

A general solution that can be used for any number(m) of sorted arrays of variable length: here m=4;

#include<stdio.h>
#include<stdlib.h>
int smallest(int *p[],int n, int *size, int *counter)
{
  int i;int min=100;
  
  for(i=0;i<n;i++)
  {
  	if(counter[i]!=size[i])
    if(*(p[i])<min)
    {
      min=*p[i];
    }
  }
  for(i=0;i<n;i++)
  {
  	if(counter[i]!=size[i])
    if(min==*p[i])
    {
	  p[i]++;
      counter[i]++;
      break;// Remove break if you want to remove duplicates
    }
  }
  return min;
}

int main()
{
  
int a0[4]={2,5,7,9};
int a1[4]={3,6,8,14};
int a2[5]={4,7,9,11,22}; 
int a3[5]={7,8,9,22,40};
int m=4;//number of arrays
int *p[4]={a0,a1,a2,a3};//array of pointer storing each array pointer
int size[4]={sizeof(a0)/sizeof(a0[0]),sizeof(a1)/sizeof(a1[0]),sizeof(a2)/sizeof(a2[0]),sizeof(a3)/sizeof(a3[0])};
  int i,k=0;
  int counter[m];
  int B[100];
  int total_size=0;
  for(i=0;i<m;i++)
  {
     counter[i]=0;
     total_size+=size[i];
  }
  //printf("%d ",total_size);
  while(k<total_size)
  {
    int s=smallest(p,m,size,counter);
    //if(s==100)   Add this if you are removing duplicates;
      // break;
    B[k++]=s;
  }
  for(i=0;i<k;i++)
    printf("%d\n",B[i]);

}

For this one it might be faster to use sort and parallel pointers?

Perform merge sort

public class CombineArrays {

public static int[] combineArrays(int[] arr1, int[] arr2){
int idx1 = 0;
int idx2 = 0;
int idx3 = 0;
int[] arr3 = new int[arr1.length+arr2.length];
while (idx1 < arr1.length || idx2 <arr2.length){
if (idx1 < arr1.length && idx2 < arr2.length && arr1[idx1] < arr2[idx2]){
arr3[idx3++] = arr1[idx1++];
}
else if (idx2 < arr2.length){
arr3[idx3++] = arr2[idx2++];
}
else if (idx1 < arr1.length){
arr3[idx3++] = arr1[idx1++];
}
}
return arr3;
}

public static void main(String[] args){
int[] arr1 = {1,2,4,7,9};
int[] arr2 ={2,8};
int[] res = combineArrays(arr1,arr2);
for (int i=0; i<res.length; ++i){
System.out.println(res[i]);
}
}

}