题解 | #提取不重复的整数#

l = 0
r = len(n) - 1

hash = {}
res_list = []
while r >= l:
#     print(n[r])
    if n[r] not in hash:
        hash[n[r]] = r
        res_list.append(n[r])
    r -= 1

res = "".join(res_list) 
print(res)