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.
Your algorithm should run in O(n2) complexity.
Follow up: Could you improve it to O(n log n) time complexity?
public class Solution { public int lengthOfLIS(int[] nums) { if (nums==null)return 0; int n=nums.length; if (n==0)return 0; int max=0; int[] dp=new int[n]; for (int i=0;i<n;i++){ dp[i]=1; for (int j=0;j<n;j++){ if (nums[j]<nums[i]&&dp[j]+1 > dp[i]){ dp[i]=dp[j]+1; } } max=Math.max(max,dp[i]); } return max; } }