Longest Increasing Subsequence

Given an integer array `nums`, return the length of the longest **strictly increasing subsequence**. A **subsequence** is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements. **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 Explanation: The longest increasing subsequence is [0,1,2,3], therefore the length is 4. ``` **Example 3:** ``` Input: nums = [7,7,7,7,7] Output: 1 Explanation: The longest increasing subsequence is [7], therefore the length is 1. ```