Package g1301_1400.s1394_find_lucky_integer_in_an_array

Class Solution

java.lang.Object
g1301_1400.s1394_find_lucky_integer_in_an_array.Solution
public class Solution extends java.lang.Object
1394 - Find Lucky Integer in an Array.

Easy

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.

Example 1:

Input: arr = [2,2,3,4]

Output: 2

Explanation: The only lucky number in the array is 2 because frequency[2] == 2.

Example 2:

Input: arr = [1,2,2,3,3,3]

Output: 3

Explanation: 1, 2 and 3 are all lucky numbers, return the largest of them.

Example 3:

Input: arr = [2,2,2,3,3]

Output: -1

Explanation: There are no lucky numbers in the array.

Constraints:

  • 1 <= arr.length <= 500
  • 1 <= arr[i] <= 500

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    findLucky(int[] arr)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • findLucky

      public int findLucky(int[] arr)