300. Longest Increasing Subsequence

Given an unsorted array of integers, find the length of longest increasing subsequence.

For example,
Given [10, 9, 2, 5, 3, 7, 101, 18],
The longest increasing subsequence is [2, 3, 7, 101], therefore the length is 4. Note that there may be more than one LIS combination, it is only necessary for you to return the length.

public class Solution {    public int lengthOfLIS(int[] nums) {        if(nums == null || nums.length == 0) {            return 0;        }        int len = nums.length, max = 0;        int[] dp = new int[len];                for(int i = 0; i < len; i++) {            dp[i] = 1;            for(int j = 0; j < i; j++) {                if(nums[i] > nums[j] && dp[j] + 1 > dp[i]) {                    dp[i] = dp[j] + 1;                }            }            max = Math.max(max, dp[i]);        }                return max;    }}