1090. 受标签影响的最大值

class Solution(object):
    def largestValsFromLabels(self, values, labels, num_wanted, use_limit):
        """
        :type values: List[int]
        :type labels: List[int]
        :type num_wanted: int
        :type use_limit: int
        :rtype: int
        """
        # 用字典，按标签统计所有值
        mydict = {}
        i = 0
        n = len(labels)
        while i < n:
            if labels[i] in mydict.keys():
                mydict[labels[i]].append(values[i])
            else:
                mydict[labels[i]] = [values[i]]
            i += 1
        # 遍历字典，每个标签中取出use_limit个数放到res中
        res = []
        for item in mydict.values():
            item.sort(reverse=True)
            res += item[:use_limit]
        # res降序排，返回sum(res[:num_wanted])
        res.sort(reverse=True)
        return sum(res[:num_wanted])