# 1394. Find Lucky Integer in an Array from collections import Counter """ given an array of integers 'arr', a lucky integer is an integer equal that has a frequency in the array equal to its value. return the largest lucky integer in the array. if there is no lucky integer, return -, a lucky integer is an integer equal that has a frequency in the array equal to its value. return the largest lucky integer in the array. if there is no lucky integer, return -1 """ class Solution(object): def findLucky(self, arr): """ :type arr: List[int] :rtype: int """ cnt = Counter(arr) return max([i for i, j in cnt.items() if i == j] + [-1]) if __name__ == "__main__": obj = Solution() print(obj.findLucky(arr=[2, 2, 3, 4])) print(obj.findLucky(arr=[1, 2, 2, 3, 3, 3])) print(obj.findLucky(arr=[2, 2, 2, 3, 3]))