题解 | #DNA序列#
DNA序列
https://www.nowcoder.com/practice/e8480ed7501640709354db1cc4ffd42a
S = input()
m = int(input())
Ratio = 0
dic = {}
for i in range(len(S) - m + 1):
Ratio = S[i : i + m].count("C") + S[i : i + m].count("G")
dic[i] = Ratio
max_rio = sorted(dic.values())[-1]
for k, v in dic.items():
if v == max_rio:
print(S[k : k + m])
break