Given a 32-bit signed integer, reverse digits of an integer.

Example 1:

Input: 123 Output: 321 Example 2:

Input: -123 Output: -321 Example 3:

Input: 120 Output: 21

思路： 1、將整數轉化成字元陣列； 2、對字元陣列進行反轉操作； 3、拼接字元陣列中的元素，進行返回即可

package main

import (
	"fmt"
	"strconv"
)

func main()  {
	intput := 123
	ret := reverse
 
(intput)
	fmt.Println(ret)
}

func reverse(x int) int {
	MIN_INT := -2147483648
	MAX_INT := 2147483647
	if (x < MIN_INT || x > MAX_INT){
		return 0
	}
	if ((x > -9) && (x < 9)){
		return x
	}
	isNegative := false
	if (x <0){
		x = (-1) * x
		isNegative = true
	}
	stringTem := strconv.
 
Itoa(x)
	stringArrs := []byte(stringTem)
	for beg, end := 0, len(stringArrs) - 1; beg < end; beg, end = beg + 1, end - 1{
		tem := stringArrs[beg]
		stringArrs[beg] = stringArrs[end]
		stringArrs[end] = tem
	}
	retBeg := 0
	for {
		if stringArrs[retBeg] == '0' {
			retBeg++
		} else {
			break
		}
	}
 

	stringRet := string(stringArrs[retBeg:])
	if isNegative == true {
		stringRet = "-" +stringRet
	}
	temRet,_ := strconv.ParseInt(stringRet,10,64)
	if (temRet < int64(MIN_INT) || temRet > int64(MAX_INT)){
		return 0
	}
	return int(temRet)


}