输入一个随机字符串，将其重新排列后，正向看与反向看一致，示例：abcba -> abcba

解题思路：将s其去重得到lt，遍历一遍lt，查看lt每个元素在s中出现的次数，出现奇数的次数为0或1次则s是回文串

s = input('请输入字符串：')
num = 0
lt = []
for i in s:
    if i not in lt:
        lt.append(i)
for j in lt:
    x = s.count('%s'%j)
    if x % 2 != 0:
        num += 1
print(num == 0 or num == 1)