add_strings.go

package main

import (
"strconv"
"strings"
)

funcaddStrings(num1string, num2string) string {
varsb strings.Builder

i, j:=len(num1)-1, len(num2)-1
carry:=0

fori>=0||j>=0 {
sum:=carry

ifi>=0 {
digit, _:=strconv.Atoi(string(num1[i]))
sum+=digit
i--
 }
ifj>=0 {
digit, _:=strconv.Atoi(string(num2[j]))
sum+=digit
j--
 }

sb.WriteString(strconv.Itoa(sum%10))
carry=sum/10
 }

ifcarry!=0 {
sb.WriteString(strconv.Itoa(carry))
 }

result:=sb.String()
reversedResult:=reverseString(result)
returnreversedResult
}

funcreverseString(sstring) string {
runes:= []rune(s)
fori, j:=0, len(runes)-1; i<j; i, j=i+1, j-1 {
runes[i], runes[j] =runes[j], runes[i]
 }
returnstring(runes)
}