题93. 复原IP地址

Python3

class Solution:
    def _restoreIpAddresses(self, s, n, index, ip, result):
        if n == 0:
            if index == len(s):
                result.append(ip)
            return

        def isNum(num):
            if 0 <= int(num) <= 255 and str(int(num)) == num:
                return True
            return False

        for i in range(index+1, len(s) + 1):
            if isNum(s[index:i])