题目

两个大数相加（这两个大数之和超过了int64），使用go语言实现这样的加法。

实现

package mainimport (\"bufio\"\"fmt\"\"os\"\"strings\")func bigNumberAdd(num1, num2 string) (result string) {num1Index := len(num1) - 1num2Index := len(num2) - 1resultIndex := 0if num1Index == -1 && num2Index == -1 {return \"0\"}for _, c := range num1 {if c < 48 || c > \'9\' {fmt.Println(\"num1 is invalid\")os.Exit(-1)}}for _, c := range num2 {if c < \'0\' || c > \'9\' {fmt.Println(\"num2 is invalid\")os.Exit(-1)}}resultIndex = num1Index + 2if num1Index < num2Index {resultIndex = num2Index + 2}_result := make([]byte, resultIndex)var cAdd byteresultIndex--for num1Index >= 0 && num2Index >= 0 {cAdd = num1[num1Index] - \'0\' + num2[num2Index] - \'0\' + _result[resultIndex]_result[resultIndex] = \'0\' + cAdd%10_result[resultIndex-1] = cAdd / 10num1Index--num2Index--resultIndex--}if num1Index == -1 {for num2Index >= 0 {cAdd = num2[num2Index] - \'0\' + _result[resultIndex]_result[resultIndex] = \'0\' + cAdd%10_result[resultIndex-1] = cAdd / 10num2Index--resultIndex--}}if num2Index == -1 {for num1Index >= 0 {cAdd = num1[num1Index] - \'0\' + _result[resultIndex]_result[resultIndex] = \'0\' + cAdd%10_result[resultIndex-1] = cAdd / 10num1Index--resultIndex--}}_result[resultIndex] = _result[resultIndex] + \'0\'result = string(_result)fmt.Println(result)result = strings.TrimPrefix(result, \"0\")return}func main() {reader := bufio.NewReader(os.Stdin)result, _, err := reader.ReadLine()if err != nil {fmt.Println(\"Read from console error:\", err)return}strSlice := strings.Split(string(result), \"+\")if len(strSlice) != 2 {fmt.Println(\"Please input a + b\")return}num1 := strings.TrimSpace(strSlice[0])num2 := strings.TrimSpace(strSlice[1])fmt.Println(bigNumberAdd(num1, num2))}