EasyNo. 2784
Check if Array is Good — LeetCode 2784 Python Solution
- Pattern
- Sorting
- Topics
- Array, Hash Table, Sorting
- Reading time
- 2 min
- Source
- leetcode.com
The problem
You are given an integer array nums. We consider an array good if it is a permutation of an array base[n].
Example
- Input
- nums = [2, 1, 3]
- Output
- false
- Explanation
- Since the maximum element of the array is 3, the only candidate n for which this array could be a permutation of base[n], is n = 3. However, base[3] has four elements but array nums has three. Therefore, it can not be a permutation of base[3] = [1, 2, 3, 3]. So the answer is false.
Python solution
class Solution:
def isGood(self, nums: List[int]) -> bool:
cnt = Counter(nums)
n = len(nums) - 1
return cnt[n] == 2 and all(cnt[i] for i in range(1, n))Complexity
- Time
- O(n)
- Space · auxiliary
- O(n)
Pattern: Sorting
Spend O(n log n) once to buy an ordering that makes the rest of the problem trivial. LeetCode 2784. Check if Array is Good is filed here because LeetCode tags it Sorting, which is the vocabulary this hub collects.
The sorting guide has the Python template for the pattern and the 401 LeetCode problems that use it.
Related problems
| No. | Problem | Difficulty |
|---|---|---|
| 2780 | Minimum Index of a Valid Split | Medium |
| 0049 | Group Anagrams | Medium |
| 0169 | Majority Element | Easy |
| 0217 | Contains Duplicate | Easy |
| 0229 | Majority Element II | Medium |
| 0268 | Missing Number | Easy |
Frequently asked questions
- How hard is LeetCode 2784. Check if Array is Good?
LeetCode 2784. Check if Array is Good is rated Easy on LeetCode.
- What is the time complexity of LeetCode 2784. Check if Array is Good?
The Python solution on this page runs in O(n).
- What is the space complexity of LeetCode 2784. Check if Array is Good?
The Python solution on this page uses O(n) auxiliary space.
- What topics does LeetCode 2784. Check if Array is Good cover?
LeetCode 2784. Check if Array is Good is tagged Array, Hash Table and Sorting on LeetCode.