#1346
Check If N and Its Double Exist
easy · verified · 41.7% accepted · 2,517 likes · top 22%
array · hash table · two pointers · binary search · sorting
Description
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.
Solution