Skip to main content

Longest Increasing Subsequence

Problem Statement

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

Leetcode Link

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

Code

Python Code
class Solution:
def lengthOfLIS(self, nums):
tails = [0] * len(nums)
size = 0
for x in nums:
i, j = 0, size
while i != j:
m = (i + j) / 2
if tails[m] < x:
i = m + 1
else:
j = m
tails[i] = x
size = max(i + 1, size)
return size