Link 👉🏻 1550. Three Consecutive Odds

💯✅ LeetCode 1550. Three Consecutive Odds | Go by Hugo

Description

Given an integer array arr, return true if there are three consecutive odd numbers in the array. Otherwise, return false.

Example 1:

• Input: arr = [2,6,4,1]
• Output: false
• Explanation: There are no three consecutive odds.

Example 2:

• Input: arr = [1,2,34,3,4,5,7,23,12]
• Output: true
• Explanation: [5,7,23] are three consecutive odds.

Constraints:

• 1 <= arr.length <= 1000
• 1 <= arr[i] <= 1000

Intuition

We have to check if there are "three consecutive odd numbers" in the array. We can iterate over the array and check if the current number and the two previous numbers are odd. If they are, we return true. If we reach the end of the array without finding three consecutive odd numbers, we return false.

Approach

1. Iterate over the array from index 2 to len(arr).
2. Check if the current number and the two previous numbers are odd. (with bitwise AND operation)
3. Once we find three consecutive odd numbers, return true.
4. If we reach the end of the array without finding three consecutive odd numbers, return false.

Complexity

• Time Complexity: $O(N)$
• Space Complexity: $O(1)$

Code

func threeConsecutiveOdds(arr []int) bool {
    for i := 2; i < len(arr); i++ {
		if (arr[i] & 1) == 1 && (arr[i - 1] & 1) == 1 && (arr[i - 2] & 1) == 1 {
			return true
		}
	}
	return false
}