GoDemo:给定数字字符串求可能的ip组合，数字顺序不变

package main

import (
"fmt"
"os"
"strconv"
)

func getip(source string) (ips []string) {

length := len(source)
if length > 12 || length < 4 {
return nil
}
if length == 4 {
ip := string(source[0]) + "." + string(source[1]) + "." + string(source[2]) + "." + string(source[3])
ips = append(ips, ip)
} else {
s := source
var ips_ [][]string
//放置三个点
for i := 0; i < length-1; i++ {
if i > 2 {
break
}
for j := i + 1; j < length-1; j++ {
if j-i > 3 {
break
}
for k := j + 1; k < length-1; k++ {
//fmt.Println(i, j, k)
if k-j > 3 {
break
}
if len(s[k:]) <= 4 {
//fmt.Println(i, j, k)
var ipt []string
ipt = append(ipt, string(s[0:i+1]))
ipt = append(ipt, string(s[i+1:j+1]))
ipt = append(ipt, string(s[j+1:k+1]))
ipt = append(ipt, string(s[k+1:]))
ips_ = append(ips_, ipt)
}

}
}
}
for _, ip := range ips_ {
for _, i := range ip {
if ii, err := strconv.Atoi(i); err != nil || ii > 255 {
goto over
}
}
ips = append(ips, ip[0]+"."+ip[1]+"."+ip[2]+"."+ip[3])
over:
}
}
return
}

func main() {
fmt.Println("处理字符串：", os.Args[1])
fmt.Println(getip(os.Args[1]))
}