题解 | DNA序列
DNA序列
https://www.nowcoder.com/practice/e8480ed7501640709354db1cc4ffd42a
import sys
sl = sys.stdin.readline().strip()
n = int(sys.stdin.readline().strip())
dict_char = {}
m = len(sl) - n + 1
for i in range(m):
dict_char[sl[i:n+i]] = (sl[i:n+i].count('C') + sl[i:n+i].count('G'))/n
dict_list = sorted(dict_char.items(),key = lambda x: x[1],reverse=True)
print(dict_list[0][0])

