方法1:使用内置sorted(默认按ASCII排序)
print("".join(sorted(input())))
方法2:冒泡排序
s = list(input())
for i in range(len(s)-1):
for j in range(len(s)-i-1):
if ord(s[j]) > ord(s[j+1]):
s[j], s[j+1] = s[j+1], s[j]
print(''.join(s))

print("".join(sorted(input())))
s = list(input())
for i in range(len(s)-1):
for j in range(len(s)-i-1):
if ord(s[j]) > ord(s[j+1]):
s[j], s[j+1] = s[j+1], s[j]
print(''.join(s))