题目:
输入形如AB-ABC-cABd-Cb@，输入待分隔长度k； 要求输出保留第一个“-”前面的字符串格式，后面的每k个字符一分格，每三个字符中，大写字母数多的三个字母转大写，小写字母数多的三个字母转小写，一样多的不处理。
输入：
AB-ABC-cABd-Cb@
2
输出：
AB-AB-CC-AB-dc-b@
思路：
题解：
head, tail = input().split("-", 1) # "-"为分隔符，1为分隔次数
k = int(input())
tail = tail.replace("-", "")
ls = ""
for i in range(0, len(tail), 3):
fen = tail[i:i+3] # 把后面的字符串以3个字符分隔
up_count = 0
low_count = 0
for c in fen: # 每3个字符分隔的串循环一次
if 'A' <= c <= 'Z':
up_count += 1
if 'a' <= c <= 'z':
low_count += 1
if up_count == low_count:
ls += fen
elif up_count > low_count:
ls += fen.upper()
else:
ls += fen.lower()
# 按长度k处理ls
new_ls = []
for j in range(0, len(ls), k):
new_ls.append(ls[j:j+k])
print(f"{head}-{'-'.join(new_ls)}")
方法二：
str_input = ""
k = int(input())
ls = []
for j in str_input:
ls.append(j)
if j == "-":
ls.append(j)
break
else:
j += 1
m = len(ls)
new_ls = []
ls_i = [] # 所有符号-的下标数
for i in range(len(str_input[m:])):
new_ls.append(str_input[i])
if str_input[i] == "-":
ls_i.append(i)
else:
continue
new_ls = new_ls[::3]
