Question 34

#Instructions from your teacher:
#Given a string s containing only digits. Return all possible valid IP addresses that can be obtained from s.
#You can return them in any order.
#A valid IP address consists of exactly four integers, each integer is between 0 and 255, 
#separated by single points and cannot have leading zeros. For example, "0.1.2.201" and "192.168.1.1" are valid IP addresses
#and "0.011.255.245", "192.168.1.312" and "192.168@1.1" are invalid IP addresses. 

#Input: s = "1111"
#Output: ["1.1.1.1"]

#Input: s = "101023"
#Output: ["1.0.10.23","1.0.102.3","10.1.0.23","10.10.2.3","101.0.2.3"]


def valid_ip1(ip):
    ip=ip.split(".")
    for i in ip: 
        if len(i) > 3 or int(i) < 0 or int(i) > 255: 
            return False
        if len(i) > 1 and int(i) == 0: 
            return False
        if len(i) > 1 and int(i) != 0 and i[0] == '0': 
            return False
    return True

def valid_ip(s): 
    
    sz = len(s) 
  
    if sz > 12: 
        return [] 
    snew = s 
    res = [] 
 
    for i in range(1, sz - 2): 
        for j in range(i + 1, sz - 1): 
            for k in range(j + 1, sz): 
                snew = snew[:k] + "." + snew[k:] 
                snew = snew[:j] + "." + snew[j:] 
                snew = snew[:i] + "." + snew[i:] 
                  
                if valid_ip1(snew): 
                    res.append(snew) 
                snew = s 
    return res 

if __name__ == "__main__":
  input_string = "0000"
  print(valid_ip(input_string))