Simple and understandable high-precision addition in C language

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  I think when you first started to learn determinant calculation in primary school , I should have been held by my mother's ears to say how I forgot to enter one again , They all fantasize about having a machine that can help them calculate , Now you can see that this is the principle of high-precision addition .

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Problem description

Its key points are simple

1. Data storage problems

When our int and longlong There is no way to meet this number of storage size, what should we do ？

The first thought is to split , It's not convenient to store a long number by breaking it into one digit after another , And that's where it comes in Array storage Methods

2. How to calculate after splitting

It's much simpler , Just like what we learned in primary school The principle of full decimal

Just know this ok 了 , Let's take a look at the code display ！

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Code display

#include<stdio.h>
#include<string.h>
char s1[505],s2[505];
int a[505],b[505],c[505];// Define both inside and outside 
int main()
{
	int la,lb,lc;
	scanf("%s",s1);
	scanf("%s",s2);// Because I don't know the length of the number , First define it as character type ·
	la=strlen(s1);// Directly calculate the length without ‘/0’
	lb=strlen(s2);
	for(int i=0;i<la;i++)
		a[la-i]=s1[i]-'0';// Turn the character array into numeric type for easy calculation , And store them in reverse order 
	for(int i=0;i<lb;i++)
		b[lb-i]=s2[i]-'0';
	lc=(lb>la)?(lb+1):(la+1);// Use the binocular operator , Because no matter how big the number is, the maximum is the longest length +1
	for(int i=0;i<=lc;i++)
	{
		c[i]+=a[i]+b[i];// because c[i] Probably not. 0, So we should also participate in accumulation 
		c[i+1]=c[i]/10;// carry 
		c[i]=c[i]%10;// Remainder 
	}
	if(c[lc]==0&&lc>0)// If the maximum is 0, Remove it 
		lc--;
	for(int i=lc;i>0;i--)
		printf("%d",c[i]);	
	return 0;
}