华为机试66：配置文件恢复

solve：create dictionary to solve

import sys
#create commend dictionary
command={'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'}
keyl=list(command.keys()) #dict key is hashable,transform to unhashable
for ss in sys.stdin:
    s=ss.lower().split()#input without distinguishing was tranformed to a list
    a=len(s)        #calculating input list length
    if a==0 or a>=3:print('unknown command')
    else:
        if a==1:
            if s[0] in keyl[0]:print(command[keyl[0]])
            else:print('unknown command')
        else:
            num=0
            knum=0
            for i in range(1,6):
                if s[0] in keyl[i].split()[0] and s[1] in keyl[i].split()[1]:
                    num+=1
                    knum=i
            if num==1:print(command[keyl[knum]])
            else:print('unknown command')