题解 | #合法IP#
合法IP
https://www.nowcoder.com/practice/995b8a548827494699dc38c3e2a54ee9?tpId=37&rp=1&ru=%2Fexam%2Foj%2Fta&qru=%2Fexam%2Foj%2Fta&sourceUrl=%2Fexam%2Foj%2Fta%3Fpage%3D1%26pageSize%3D50%26search%3D%26tpId%3D37%26type%3D37&difficulty=&judgeStatus=&tags=&title=90&gioEnter=menu
ip = input() def valid(ip): if len(ip.split(".")) != 4: return False for s in ip.split("."): # 可能包含+号 if not s.isdigit(): return False # 可能从0开始 if len(s) == 0 or int(s) > 256 or int(s) < 0 or (s.startswith("0") and len(s) > 1): return False return True if valid(ip): print("YES") else: print("NO")