[LeetCode] #300 Longest Increasing Subsequence

public class Solution {
    // state: f[i] - length of LIS for nums[0...i]
    // function: f[i] = (Max(f[j] + 1), if nums[j] < nums[i]), for all 0 < j < i
    // initialze: f[0] = 1
    // result: Max(f[0...nums.length-1]) //Attn!
    public int lengthOfLIS(int[] nums) {
        if (nums == null || nums.length == 0) {
            return 0;
        }
        int[] f = new int[nums.length];
        int maxLength = 1;
        for (int i = 0; i < nums.length; i++) {
            f[i] = 1;
            for (int j = 0; j < i; j++) {
                if (nums[j] < nums[i]) {
                    f[i] = Math.max(f[i], f[j] + 1);
                    maxLength = Math.max(maxLength, f[i]);
                }
            }
        }
        return maxLength;
    }
}