7. 整数反转

func reverse(x int) int {
var restr string
if x < 0 {
strin := strconv.Itoa(x)[1:]
fmt.Println(len(strin))
for i := len(strin) - 1; i >=0; i-- {
restr += string(strin[i])
fmt.Println(restr)
}
restr = “-” + restr
} else {
strin := strconv.Itoa(x)
fmt.Println(len(strin))
for i := len(strin) - 1; i >=0; i-- {
restr += string(strin[i])
fmt.Println(restr)
}
}
b, _ := strconv.Atoi(restr)
if b < math.MinInt32 || b > math.MaxInt32 {
return 0
}
return b
}

func reverse(x int) int {
y := 0
for x!=0 {
y = y*10 + x%10
if !( -(1<<31) <= y && y <= (1<<31)-1) {
return 0
}
x /= 10
}
return y
}