思路:哈希表
代码:
def function(s:str) ->str:
n = len(s)
counterStr = {}
for i in s:
counterStr[i] = counterStr.get(i,0) + 1
leftStr = []
midStr = []
for key,val in counterStr.items():
if val %2 ==1:
midStr.append(key)
if val >= 2:
for _ in range(val//2):
leftStr.append(key)
leftStr.sort()
leftStr_str = ''.join(leftStr)
midStr.sort()
ans = leftStr_str + midStr[0] + leftStr_str[::-1]
return ans
s = 'abczcccddzz'
print(function(s))