Description
Given an array of integers arr, a lucky integer is an integer 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.
Examples
Input:
arr = [2,2,3,4]Output:
2Explanation:
2 appears 2 times.
Input:
[1, 2, 2, 3, 3, 3]Output:
3Explanation:
1 appears 1 time, 2 appears 2 times, and 3 appears 3 times. All three are lucky integers, but 3 is the largest.
Input:
[5, 5, 5, 5, 7, 7, 7, 7, 7]Output:
-1Explanation:
5 appears 4 times (not equal to 5) and 7 appears 5 times (not equal to 7). Since no integer has a frequency equal to its value, return -1.
Constraints
- •
1 ≤ arr.length ≤ 500 - •
1 ≤ arr[i] ≤ 500