题解 | #DNA序列#

找出所有subset，再计算哪个GC比最高 打印GC比最高的那个

while True:
    try:
        s = input()
        n = int(input())
        subset = []
        res = {}
        for i in range(len(s)-n+1):
            subset.append(s[i:i+n])
        for i in subset:
            if 'C' in i or 'G' in i:
                res[i] = (i.count('C') + i.count('G'))/n
        res = sorted(res.items(), key = lambda x: x[1], reverse = True)
        print(res[0][0])
    except:
        break