README_EN.md

comments	difficulty	edit_url	tags
true	Easy	https://github.com/doocs/leetcode/edit/main/solution/2200-2299/2229.Check%20if%20an%20Array%20Is%20Consecutive/README_EN.md	Array Hash Table Sorting

2229. Check if an Array Is Consecutive 🔒

中文文档

Description

Given an integer array nums, return true if nums is consecutive, otherwise return false.

An array is consecutive if it contains every number in the range [x, x + n - 1] (inclusive), where x is the minimum number in the array and n is the length of the array.

 

Example 1:

Input: nums = [1,3,4,2]
Output: true
Explanation:
The minimum value is 1 and the length of nums is 4.
All of the values in the range [x, x + n - 1] = [1, 1 + 4 - 1] = [1, 4] = (1, 2, 3, 4) occur in nums.
Therefore, nums is consecutive.

Example 2:

Input: nums = [1,3]
Output: false
Explanation:
The minimum value is 1 and the length of nums is 2.
The value 2 in the range [x, x + n - 1] = [1, 1 + 2 - 1], = [1, 2] = (1, 2) does not occur in nums.
Therefore, nums is not consecutive.

Example 3:

Input: nums = [3,5,4]
Output: true
Explanation:
The minimum value is 3 and the length of nums is 3.
All of the values in the range [x, x + n - 1] = [3, 3 + 3 - 1] = [3, 5] = (3, 4, 5) occur in nums.
Therefore, nums is consecutive.

 

Constraints:

• 1 <= nums.length <= 105
• 0 <= nums[i] <= 105

Solutions

Solution 1

Python3

class Solution:
    def isConsecutive(self, nums: List[int]) -> bool:
        mi, mx = min(nums), max(nums)
        n = len(nums)
        return len(set(nums)) == n and mx == mi + n - 1

Java

class Solution {
    public boolean isConsecutive(int[] nums) {
        int mi = nums[0];
        int mx = nums[0];
        Set<Integer> s = new HashSet<>();
        for (int v : nums) {
            mi = Math.min(mi, v);
            mx = Math.max(mx, v);
            s.add(v);
        }
        int n = nums.length;
        return s.size() == n && mx == mi + n - 1;
    }
}

C++

class Solution {
public:
    bool isConsecutive(vector<int>& nums) {
        unordered_set<int> s(nums.begin(), nums.end());
        int mi = *min_element(nums.begin(), nums.end());
        int mx = *max_element(nums.begin(), nums.end());
        int n = nums.size();
        return s.size() == n && mx == mi + n - 1;
    }
};

Go

func isConsecutive(nums []int) bool {
	s := map[int]bool{}
	mi, mx := slices.Min(nums), slices.Max(nums)
	for _, x := range nums {
		s[x] = true
	}
	return len(s) == len(nums) && mx == mi+len(nums)-1
}