public class Solution
extends Object
1346 - Check If N and Its Double Exist\.
Easy
Given an array `arr` of integers, check if there exists two integers `N` and `M` such that `N` is the double of `M` ( i.e. `N = 2 * M`).
More formally check if there exists two indices `i` and `j` such that :
* `i != j`
* `0 <= i, j < arr.length`
* `arr[i] == 2 * arr[j]`
**Example 1:**
**Input:** arr = [10,2,5,3]
**Output:** true
**Explanation:** N `= 10` is the double of M `= 5`,that is, `10 = 2 * 5`.
**Example 2:**
**Input:** arr = [7,1,14,11]
**Output:** true
**Explanation:** N `= 14` is the double of M `= 7`,that is, `14 = 2 * 7`.
**Example 3:**
**Input:** arr = [3,1,7,11]
**Output:** false
**Explanation:** In this case does not exist N and M, such that N = 2 \* M.
**Constraints:**
* `2 <= arr.length <= 500`
* `-10^3 <= arr[i] <= 10^3`