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
class Solution:
    def checkIfExist(self, arr: List[int]) -> bool:
        if len(arr) == 0 or len(arr) == 1:
            return False
        else:
            for i in range(len(arr) - 1):
                for j in range(i + 1, len(arr)):
                    if arr[i] == 2 * arr[j] or arr[j] == 2 * arr[i]:
                        return True
            return False
class Solution:
    def checkIfExist(self, arr: List[int]) -> bool:
        if len(arr) == 0 or len(arr) == 1:
            return False
        else:
            for i in range(len(arr) - 1):
                for j in range(i + 1, len(arr)):
                    if arr[i] == 2 * arr[j] or arr[j] == 2 * arr[i]:
                        return True
            return False