Question

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

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

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;
  }
}

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;
  }
};

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
}