CareerCup

//m is length of array a & n is length of  array b
public int[] merge_sort(int[] a,int[] b, int m, int n)
{
	a = Arrays.copyOf(a,a.length+b.length);
	int i = m-1;
	int j = n-1;
	int k = m+n-1;

	while(i>=0 && j>=0)
	{
		if(a[i] > b[j])
			a[k--] = a[i--];
		else
			a[k--] = b[j];
	}
	while(j>=0)
	{
		a[k--] = b[j];
	}
	
	return a;
}

var arrayB = new int[] { 1, 3, 5, 7, 10 };
var arrayA = new int[] { 0, 1, 2, 6, 8, 12, 13, 14,15 };

var finalArray = new int[arrayA.Length + arrayB.Length];

int indexA = 0;
int indexB = 0;


int index = 0;
while(indexA < arrayA.Length)
{
while(indexB < arrayB.Length)
{
int elementA = arrayA[indexA];
int elementB = arrayB[indexB];

if(elementA <= elementB)
{
finalArray[index] = elementA;
index++;
indexA++;
break;
}else
{
finalArray[index] = elementB;
index++;
indexB++;
continue;

}
}

if(indexB == arrayB.Length)
{
for(int i= indexA ;i< arrayA.Length; i++)
{
finalArray[index] = arrayA[i];
index++;
}
break;
}

}

This is a cleaned up version of answer 1.

public int[] merge(int[] a, int[] b) {
  int i = 0;
  int j = 0;
  int index = 0;
  int[] result = new int[a.length + b.length);
  while (i < a.length && j < b.length) {
    if (a[i] <= b[j]) {
      result[index] = a[i];
      i++;
    } else {
      result[index] = b[j];
      j++;
    }
    index++;
  }
  //only one of the below for loops will execute, depending on if i or j exceeded
  //the bounds of a or b (respectively)
  for(; i < a.length; i++) {
    result[index] = a[i];
    index++;
  }
  for (; j < b.length; j++) {
    result[index] = b[j];
    index++;
  }
  return result;
}

public int[] mergeArray(int A[], int []B){
int []C =new int[A.length+B.length];
int indexA=0, indexB=0,indexC=0;
while(indexC <C.length){
if(indexA <A.length && A[indexA] <= B[indexB])
{
C[indexC]=A[indexA];
indexA++;
}
else if(indexB < B.length){
C[indexC]=B[indexB];
indexB++;
}
indexC++;
}

return C;
}

int A[];
int B[];
int C[];

int i=0;j=0;
while(i<A.length && j<B.length)
{
 if(A[i]<=B[j])
    C[k]=A[i]
    k++;
    i++;
 else
    C[k]=B[j];
    k++;
    j++;
}
while(i<A.length)
 C[k]=A[i];
 i++;
 k++;
while(j<B.length)
 C[k]=B[j];
 k++;j++;