check_if_n_and_its_double_exist.py

'''
1346. Check If N and Its Double Exist
Solved
Easy
Topics
Companies
Hint

Given an array arr of integers, check if there exist 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: For i = 0 and j = 2, arr[i] == 10 == 2 * 5 == 2 * arr[j]

Example 2:
Input: arr = [3,1,7,11]
Output: false
Explanation: There is no i and j that satisfy the conditions.

Constraints:
    2 <= arr.length <= 500
    -103 <= arr[i] <= 103
'''

class Solution:
    def checkIfExist(self, arr: List[int]) -> bool:
        for i_idx, i in enumerate(arr):
            for j_idx, j in enumerate(arr):
                if i_idx != j_idx:
                    if i_idx >= 0 and j_idx < len(arr):
                        if i == 2 * j:
                            return True
        return False