- Difficulty: Medium
- Tags: LeetCode, Medium, Greedy, Array, Hash Table, Heap (Priority Queue), leetcode-659, O(n), O(1)
Problem
You are given an integer array nums
that is sorted in non-decreasing order.
Determine if it is possible to split nums
into one or more subsequences such that both of the following conditions are true:
- Each subsequence is a consecutive increasing sequence (i.e. each integer is exactly one more than the previous integer).
- All subsequences have a length of
3
or more.
Return true
if you can split nums
according to the above conditions, or false
otherwise.
A subsequence of an array is a new array that is formed from the original array by deleting some (can be none) of the elements without disturbing the relative positions of the remaining elements. (i.e., [1,3,5]
is a subsequence of [1,2,3,4,5]
while [1,3,2]
is not).
Example 1:
Input: nums = [1,2,3,3,4,5] Output: true Explanation: nums can be split into the following subsequences: [1,2,3,3,4,5] --> 1, 2, 3 [1,2,3,3,4,5] --> 3, 4, 5
Example 2:
Input: nums = [1,2,3,3,4,4,5,5] Output: true Explanation: nums can be split into the following subsequences: [1,2,3,3,4,4,5,5] --> 1, 2, 3, 4, 5 [1,2,3,3,4,4,5,5] --> 3, 4, 5
Example 3:
Input: nums = [1,2,3,4,4,5] Output: false Explanation: It is impossible to split nums into consecutive increasing subsequences of length 3 or more.
Constraints:
1 <= nums.length <= 104
-1000 <= nums[i] <= 1000
nums
is sorted in non-decreasing order.