3151. Special Array I

Problem

An array is considered special if every pair of its adjacent elements contains two numbers with different parity.

You are given an array of integers nums. Return true if nums is a special array, otherwise, return false.

https://leetcode.com/problems/special-array-i/

Example 1:

Input: nums = [1]
Output: true
Explanation:
There is only one element. So the answer is true.

Example 2:

Input: nums = [2,1,4]
Output: true
Explanation:
There is only two pairs: (2,1) and (1,4), and both of them contain numbers with different parity. So the answer is true.

Example 3:

Input: nums = [4,3,1,6]
Output: false
Explanation:
nums[1] and nums[2] are both odd. So the answer is false.

Constraints:

• 1 <= nums.length <= 100
• 1 <= nums[i] <= 100

Test Cases

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class Solution:
    def isArraySpecial(self, nums: List[int]) -> bool:

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import pytest

from solution import Solution


@pytest.mark.parametrize('nums, expected', [
    ([1], True),
    ([2,1,4], True),
    ([4,3,1,6], False),
])
class Test:
    def test_solution(self,nums, expected):
        sol = Solution()
        assert sol.isArraySpecial(nums) == expected

Thoughts

Code

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class Solution:
    def isArraySpecial(self, nums: list[int]) -> bool:
        prev = nums[0] & 1
        for i in range(1, len(nums)):
            if nums[i] & 1 == prev:
                return False
            prev = 1 - prev

        return True

参考资料

• 反向引用

  • 3152. Special Array II

许可协议

本文除了题目描述（Problem）部分之外，其他内容由 Calf 原创，采用 CC BY-NC-SA 4.0 许可协议，转载请注明出处。

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