Huge number multiplication (C language)

In the last blog, we realized the addition and subtraction of huge numbers , Now let me fill in the hole left at the end of my last blog —— Multiplication of huge numbers .
It is easier to realize multiplication than addition and subtraction , We can analogy multiplication under decimal system to realize manual process .
Since the decimal multiplication is so, so should the multiplication under the ten thousand system , But how to solve the storage problem of each calculation result , This problem bothered me for a long time when I was programming .
It's very simple , Is that we put every round （ Or every time ） The calculation result of is directly stored in the array of our huge number of results in 10000 decimal .
by the way , In the final result, the number of digits of a huge number should be the sum of two multiplied huge digits ( In decimal ).

Let's take a look at the core code ：

void multiInfor(HUGE_NUM *NUM1, HUGE_NUM *NUM2, HUGE_NUM *NUM3) {
    
	int i;
	int j;
	int count1 = (NUM1->count+3) / 4;
	int count2 = (NUM2->count+3) / 4;
	int temp;
	int cur;
	int next;
	NUM3->sign = NUM1->sign ^ NUM2->sign;
	for (i = 0; i < count1; i++) {
    
		for (j = 0; j < count2; j++) {
    
			temp = NUM1->value[i] * NUM2->value[j] + NUM3->value[i+j];
			cur = temp % 10000;
			next = temp / 10000;
			NUM3->value[i+j] = cur;
			NUM3->value[i+j+1] = next;
		}
	}
}

Other codes are the same as those of the addition and subtraction of huge numbers , You can get what you need in my last blog .
thus , A huge number of projects are over , As for decimal and division, I still have some deficiencies in time and ability, and I can't fully realize it for the time being .
All the guidance of this project comes from teacher Zhu Hong of wechat .