将整数拆分成四份

class Solution(object):
    def helper(self, s, dotnum, ret, rets):
        if dotnum > 4 or (len(s) / 3 > 4-dotnum):
            return
        if len(s) == 0:
            if dotnum == 4:
                rets.append(ret)
            return
        for i in range(1, 4):
            tmp = s[:i]
            if (dotnum == 3 and i > len(s)) or (i > 1 and s[0] == '0') or (int(tmp) > 255):
                continue
            self.helper(s[i:], dotnum+1, ret+'.'+tmp if len(ret) > 0 else tmp, rets)
    def restoreIpAddresses(self, s):
        rets = []
        self.helper(s, 0, '', rets)
        return len(rets)
s = input()
print(Solution().restoreIpAddresses(s))
for i in range(0,4):
    print(i)