题解 | #DNA序列#
DNA序列
https://www.nowcoder.com/practice/e8480ed7501640709354db1cc4ffd42a
def cal(s):
n = len(s)
tmp = 0
for i in s:
if i =='G' or i=='C':
tmp+=1
return tmp/n
n = input().strip()
m = int(input())
re = []
for i in range(len(n)-m+1):
t = n[i:i+m]
re.append([t,cal(t)])
re = sorted(re,key=lambda x:x[1],reverse=True)
print(re[0][0])
