题解 | DNA序列
DNA序列
https://www.nowcoder.com/practice/e8480ed7501640709354db1cc4ffd42a
s = input()
n = int(input())
data = {}
for i in range(len(s)-n+1):
_s = s[i:i+n]
percent = (_s.count("C") + _s.count("G"))/len(s)
data.setdefault(percent, []).append(_s)
data = sorted(data.items(), key=lambda x: x[0], reverse=True)
print(data[0][1][0])
