A30364.【算法】加法

#include<iostream>
using namespace std;
string add(string A,string B){
	string C="";
	int a[300]={0},b[300]={0},sum[301]={0},lena=A.length(),lenb=B.length(),i=0,max=(lena>lenb?lena:lenb),x=0,digs=max;
	while(i<max){
		if(i<lena) a[i]=A[lena-i-1]-'0';
		if(i<lenb) b[i]=B[lenb-i-1]-'0';
		sum[i]=a[i]+b[i]+x;
		x=sum[i]/10;
		sum[i]%=10;
		i++;
	}
	digs+=x;
	if(x){
		sum[i]=a[i]+b[i]+x;
		x=sum[i]/10;
		sum[i]%=10;
	}
	for(int i=0;i<digs;i++)
		C+=sum[digs-i-1]+'0';
	return C;
}
int main(){
	string A,B;
	cin>>A>>B;
	cout<<add(A,B);
	return 0;
}