题解 | #整数与IP地址间的转换#

def ip2int(ip):
    i1,i2,i3,i4 = map(int, ip.split('.'))
    return i1 * pow(256, 3) + i2 * pow(256, 2) + i3 * 256 + i4

def int2ip(i):
    li = []
    for _ in range(4):
        v = i % 256
        i = (i - v) // 256
        li.insert(0,str(v))
    return '.'.join(li)

while True:
    try:
        ip = input()
    except EOFError:
        break
    if '.' in ip:
        print(ip2int(ip))
    else:
        print(int2ip(int(ip)))