#include 
     
      #include 
      
       using namespace std;int* BigNumberMulti(int arr1[], int length1, int arr2[], int length2){	int len = length1 + length2;	int* ret = new int[len];	memset(ret, 0, sizeof(int)*len);	for (int i = 0; i < length1; i++)	{		int x = i;		for (int j = 0; j < length2; j++)		{			ret[x++] += arr1[i] * arr2[j];		}	}	for (int k = 0; k < len-1; k++)	{		if (ret[k] > 10)		{			ret[k + 1] += ret[k] / 10;			ret[k] = ret[k] % 10;		}	}	return ret;}int main(){	int arr1[] = { 1,2,3,4,5,6,7,8,9 };	int arr2[] = { 9,8,7,6,5,4,3,2,1 };	int len1 = sizeof(arr1) / sizeof(arr1[0]);	int len2 = sizeof(arr2) / sizeof(arr2[0]);	int resultLen = len1 + len2;	int* result = BigNumberMulti(arr1, len1 , arr2, len2);	for (int i = resultLen -1; i >= 0; i--)	{		cout << result[i] << " " ;	}	cout << endl;	delete[] result;    return 0;}