#include <iostream>
#include <algorithm>
#include <iterator>

using namespace std;

int arrayA[10] = {1, 3, 5, 7, 9};
int arrayB[] = {2, 4, 6, 8, 10};
const int sizeB = sizeof arrayB / sizeof *arrayB;
const int sizeA = sizeof arrayA / sizeof *arrayA - sizeB;

int* mergeArray(int *arrayA, int sizeA, int *arrayB, int sizeB)
{
 if (arrayA == NULL || arrayB == NULL || sizeA < 0 || sizeB < 0)
 return NULL;

 int posA = sizeA - 1;
 int posB = sizeB - 1;

 while (posA >= 0 && posB >= 0)
 {
 if (arrayA[posA] < arrayB[posB])
 {
  arrayA[posA + posB + 1] = arrayB[posB];
  posB--;
 }
 else
 {
  arrayA[posA + posB + 1] = arrayA[posA];
  posA--;
 }
 copy(arrayA, arrayA + 10, ostream_iterator<int>(cout, " "));
 system("pause");
 }

 return arrayA;
}

void main()
{
 int *result = mergeArray(arrayA, sizeA, arrayB, sizeB);

 copy(result, result + 10, ostream_iterator<int>(cout, " "));
 cout << endl;
}

int* mergeArray(int *arrayA, int sizeA, int *arrayB, int sizeB)
{
 if (arrayA == NULL || arrayB == NULL || sizeA < 0 || sizeB < 0)
 return NULL;

 int posA = sizeA - 1;
 int posB = sizeB - 1;

 while (posA >= 0 && posB >= 0)
 {
 if (arrayA[posA] < arrayB[posB])
 {
  arrayA[posA + posB + 1] = arrayB[posB];
  posB--;
 }
 else
 {
  arrayA[posA + posB + 1] = arrayA[posA];
  posA--;
 }
 copy(arrayA, arrayA + size, ostream_iterator<int>(cout, " "));
 system("pause");
 }

 //出现两种情形：
 //1. posA < 0 && posB >= 0
 //2. posA >= 0 && posB < 0
 //只有第1种情形需要进行处理
 if (posA < 0 && posB >= 0)
 {
 while (posB >= 0)
 {
  arrayA[posA + posB + 1] = arrayB[posB];
  posB--;
 }
 } 
 return arrayA;
}