LeetCode 1550. There are three consecutive arrays of odd numbers

1550. There are three consecutive odd arrays

Give you an array of integers arr, Please judge whether three consecutive elements in the array are odd ： If there is , Please return true ; otherwise , return false .

Example 1：

 Input ：arr = [2,6,4,1]
 Output ：false
 explain ： There is no case where three consecutive elements are odd .

Example 2：

 Input ：arr = [1,2,34,3,4,5,7,23,12]
 Output ：true
 explain ： There is a case where three consecutive elements are odd , namely  [5,7,23] .

Tips ：

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

Two 、 Method 1

enumeration

class Solution {
    
    public boolean threeConsecutiveOdds(int[] arr) {
    
        int k = 0;
        for (int i = 0; i < arr.length; i++) {
    
            if ((arr[i] & 1) == 1) {
    
                k++;
                if (k == 3) {
    
                    return true;
                }
            } else {
    
                k = 0;
            }
        }
        return false;
    }
}

Complexity analysis

• Time complexity ：O(n).
• Spatial complexity ：O(1).

3、 ... and 、 Method 2

enumeration

class Solution {
    
    public boolean threeConsecutiveOdds(int[] arr) {
    

        for (int i = 0; i < arr.length - 2; i++) {
    
            if ((arr[i] & 1) == 1 && (arr[i + 1] & 1) == 1 && (arr[i + 2] & 1) == 1) {
    
                return true;
            }
               
        }
        return false;
    }
}

Complexity analysis

• Time complexity ：O(n).
• Spatial complexity ：O(1).