7. 整数反转

算法链接

https://leetcode-cn.com/problems/reverse-integer/solution/zheng-shu-fan-zhuan-by-leetcode/

解法

package main
import (
    "fmt"
    "math"
    "strconv"
)
func main() {
    x := 1534236469
    x = reverse(x)
    fmt.Println(x)
}
// 用字符串的解法
func reverse(x int) int {
    f := false
    if x < 0 {
        x *= -1
        f = true
    }
    str := strconv.Itoa(x)
    var newStr string
    l := len(str)
    for i := l - 1; i >= 0; i-- {
        newStr += string(str[i])
    }
    x, _ = strconv.Atoi(newStr)
    if f {
        x *= -1
    }
    if x > math.MaxInt32 || x < math.MinInt32 {
        x = 0
    }
    return x
}
// 用取余加除法的方式做
func reverse1(x int) int {
    n := 0
    for x != 0 {
        n = n * 10 + x % 10
        x = x / 10
    }
    if n > math.MaxInt32 || n < math.MinInt32 {
        n = 0
    }
    return n
}