1550. Three Consecutive Odds

Time: O(n)

Space: O(1)

Approach

Linear scan counting consecutive odd numbers; reset on even.

Key Techniques

Array problems involve manipulating elements stored in a contiguous block of memory. Key techniques include two-pointer traversal, prefix sums, sliding windows, and in-place partitioning. In C#, arrays are zero-indexed and fixed in size — use List<T> when you need dynamic resizing.

1550.cs

// Approach: Linear scan counting consecutive odd numbers; reset on even.
// Time: O(n) Space: O(1)

public class Solution
{
    public bool ThreeConsecutiveOdds(int[] arr)
    {
        int cnt = 0;
        for (int i = 0; i < arr.Length; i++)
        {
            if (arr[i] % 2 > 0)
                cnt++;
            else
                cnt = 0;

            if (cnt == 3)
                return true;
        }

        return false;
    }
}

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