2017 网易 [编程题] 消除重复元素

输入包括两行：
第一行为序列长度n(1 ≤ n ≤ 50)
第二行为n个数sequence[i](1 ≤ sequence[i] ≤ 1000)，以空格分隔

输出消除重复元素之后的序列，以空格分隔，行末无空格

9
100 100 100 99 99 99 100 100 100

99 100

def read_data():
num = int(raw_input())
sequence = map(lambda x: int(x), raw_input().split())
return num, sequence
def remove_duplicate(num,sequence):
if num<=0:
return sequence
result = []
valuemap =dict()
for i in range(num-1,-1,-1):
if sequence[i] in valuemap.keys():
continue
else:
valuemap[sequence[i]]=0
result.insert(0, sequence[i])
return map(lambda x: str(x), result)
num, sequence = read_data()
result = remove_duplicate(num, sequence)
print ' '.join(result)