题解 | #配置文件恢复#

import sys
#判断s字符串是否是以a字符串开始
def is_sucessed(a,s):
    if len(a) > len(s):
        return False
    for i in range(len(a)):
        if a[i] != s[i]:
            return False
    return True

code = [['reset','reset what'],
['reset board','board fault'],
['board add','where to add'],
['board delete','no board at all'],
['reboot backplane','impossible'],
['backplane abort','install first']]
for line in sys.stdin:
    a = line.strip().split(' ')
    if len(a) == 1:
        if is_sucessed(a[0],code[0][0]):
            print(code[0][1])
        else:
            print('unknown command')
    else:
        sucess = 0
        p = 'unknown command'
        for i in range(1,6):
            t = code[i][0].split(' ')
            if is_sucessed(a[0],t[0]) and is_sucessed(a[1],t[1]):
                sucess += 1
                p = code[i][1]
		#如果匹配成功只有一次，则p会被改变为正确的输出。当被改变2次及以上，sucess大于1，此时p的值不会输出了，被改变成什么就不重要了
        if sucess == 1:
            print(p)
        else:
            print('unknown command')