求两个有序数组的共同元素，比如数组a={1,2,3,8,9}和b={8,9,10},则输出output={8,9}

// 找出两个数组的共同元素
int* FindCommon(int* a, int* b, int nA, int nB, int& nOut)
{
    int i = 0;
    int j = 0 ;
	vector<int> vec_comm;

	int* output = NULL;
	
    while (i < nA && j < nB)
    {
        if (a[i] < b[j])
            ++i ;
        else if(a[i] == b[j])
        {
			vec_comm.push_back(a[i]);
            cout << a[i] << endl ;
            ++i ;
            ++j ;
        }
        else// a[i] > b[j]
            ++j ;
    }

	nOut = vec_comm.size();

	int nCoun = 0;
	if (nOut>0)
	{
		output=new int[nOut];
		vector<int>::iterator itorComm;

		for(itorComm=vec_comm.begin(); itorComm!=vec_comm.end(); itorComm++)
		{
			output[nCoun] = *itorComm;
			nCoun++;
		}
	}

	return output;
}

测试代码

int main()
{
	int* a= new int[6];
	int* b= new int[3];
	
	a[0]=2;
	a[1]=3;
	a[2]=4;
	a[3]=6;
	a[4]=8;
	a[5]=9;
	
	b[0]=8;
	b[1]=9;
	b[2]=10;

	int nOut = 0;

	int* output = FindCommon(a, b, 6, 3, nOut);

	for (int i=0; i<nOut; i++)
	{
		cout << output[i] << "," ;
	}

	cout << endl;
	
	delete[] a;
	a=NULL;
	delete[] b;
	b=NULL;
	
	delete[] output;
	output=NULL;

	cout << endl;
	
	return 0;
}