题解 | #字符串出现次数的TopK问题#

字符串出现次数TopK问题的python实现：

#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# return topK string
# @param strings string字符串一维数组 strings
# @param k int整型 the k
# @return string字符串二维数组
#
class Solution:
    def topKstrings(self , strings: List[str], k: int) -> List[List[str]]:
        # write code here
        if k==0:
            return []
        mydict = {}
        
        # 构建哈希表
        for strs in strings:
            if strs not in mydict:
                mydict[strs] = 1
            else:
                mydict[strs]+=1
            
        # 对哈希表排序
        mylist = []
        for key, val in mydict.items():
            mylist.append([key, val])
        ans_list = self.fasts(mylist)
        if k>=len(ans_list):
            return ans_list
        else:
            return ans_list[:k]
        
    def fasts(self, mylist):
        if len(mylist)<=1:
            return mylist
        a = mylist[0]
        left = [i for i in mylist[1:] if (i[1]>a[1] or (i[1]==a[1] and i[0]<a[0]))]
        right = [i for i in mylist[1:] if (i[1]<a[1] or (i[1]==a[1] and i[0]>a[0]))]
        return self.fasts(left)+[a]+self.fasts(right)