Given an int array `nums` of length `n`. Split it into strictly decreasing subsequences. Output the min number of subsequences you can get by splitting.\n\n**Example 1:**\n```\nInput: [5, 2, 4, 3, 1, 6]\nOutput: 3\nExplanation:\nYou can split this array into: [5, 2, 1], [4, 3], [6]. And there are 3 subsequences you get.\nOr you can split it into [5, 4, 3], [2, 1], [6]. Also 3 subsequences.\nBut [5, 4, 3, 2, 1], [6] is not legal because [5, 4, 3, 2, 1] is not a subsuquence of the original array.\n```\n\n**Example 2:**\n```\nInput: [2, 9, 12, 13, 4, 7, 6, 5, 10]\nOutput: 4\nExplanation: [2], [9, 4], [12, 10], [13, 7, 6, 5]\n```\n\n**Example 3:**\n```\nInput: [1, 1, 1]\nOutput: 3\nExplanation: Because of the strictly descending order you have to split it into 3 subsequences: [1], [1], [1]\n```\n\n<details> \n  <summary>Challenge</summary>\n\nO(nlogn) time.\n</details>\n\n#\n\n<details> \n  <summary>Solution</summary>\n\nJava: https://leetcode.com/playground/D2aYgBVB\nTime complexity: O(nlogn).\nSpace complexity: O(n).\n</details>\n\n#\n\n<details> \n  <summary>Related problems</summary>\n\n* https://leetcode.com/problems/longest-increasing-subsequence\n</details>

Given an int array nums of length n. Split it into strictly decreasing subsequences. Output the min number of subsequences you can get by splitting.\n\nExample 

Google | Summer Intern OA 2019 | Decreasing Subsequences