华为机试测试- 大数相加

import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
public static void main(String[] args) {
Scanner scanner=new Scanner(System.in);
String t1=scanner.next();
String t2=scanner.next();
System.out.println(getStr(t1, t2));
scanner.close();
}

public static String getStr(String a,String b)
{
int l=a.length();
int s=b.length();
String longString=l>s?a:b;
String shortString=l<=s?a:b;
l=longString.length();
s=shortString.length();
longString=new StringBuilder(longString).reverse().toString();
shortString=new StringBuilder(shortString).reverse().toString();
StringBuilder stringBuilder=new StringBuilder();
boolean carry=false;
for(int i=0;i<s;i++)
{
char cl=longString.charAt(i);
char cs=shortString.charAt(i);
int il=cl-'0';
int is=cs-'0';
int nx=il+is+(carry?1:0);
if(nx>9)
{
carry=true;
stringBuilder.append((char)('0'+nx-10));
}
else {
carry=false;
stringBuilder.append((char)('0'+nx));
}
}
if(s==l && carry)
{
stringBuilder.append('1');
return stringBuilder.toString();
}
String str=longString.substring(s,l);
for(int i=0;i<str.length();i++)
{
char c=str.charAt(i);
int nx=c-'0'+(carry?1:0);
if(nx>9)
{
carry=true;
stringBuilder.append((char)('0'+nx-10));
}
else {
carry=false;
stringBuilder.append((char)('0'+nx));
}
}
if(carry)
stringBuilder.append('1');
return stringBuilder.reverse().toString();
}
}