300. Longest Increasing Subsequence

Given an integer array nums, return the length of the longest strictly increasing subsequence.

Example 1:

Input: nums = [10,9,2,5,3,7,101,18]
Output: 4
Explanation: The longest increasing subsequence is [2,3,7,101], therefore the length is 4.

Example 2:

Input: nums = [0,1,0,3,2,3]
Output: 4

Example 3:

Input: nums = [7,7,7,7,7,7,7]
Output: 1

Constraints:

• 1 <= nums.length <= 2500
• -104 <= nums[i] <= 104

Follow up: Can you come up with an algorithm that runs in O(n log(n)) time complexity?

def lengthOfLIS(self, nums: List[int]) -> int:
	stack = []

	for num in nums:
		if not stack or num > stack[-1]:
			stack.append(num)
		else:
			left, right = 0, len(stack) - 1
			while left < right:
				mid = left + (right - left) // 2
				if stack[mid] < num:
					left = mid + 1
				else:
					right = mid

			stack[left] = num

	return len(stack)