题解 | 好串
好串
https://www.nowcoder.com/practice/9b072237ebdd4dd99562f01cbf594fac
s = input().strip()
# 检查长度是否为偶数
if len(s) % 2 != 0:
print("Bad")
exit()
# 检查是否只包含a和b
for c in s:
if c not in {'a', 'b'}:
print("Bad")
exit()
count_a = 0
count_b = 0
for c in s:
if c == 'a':
count_a += 1
else:
count_b += 1
# 任何前缀中a的数量不能少于b的数量
if count_b > count_a:
print("Bad")
exit()
# 检查a和b的总数是否相等
if count_a != count_b:
print("Bad")
else:
print("Good")
