LeetCode – LongestIncreasing Subsequence (Java)

public int lengthOfLIS(int[] nums) {

    if(nums==null || nums.length==0)

        return 0;

    int[] max = new int[nums.length];

    for(int i=0; i<nums.length; i++){

        max[i]=1;

        for(int j=0; j<i;j++){

            if(nums[i]>nums[j]){

                max[i]=Math.max(max[i], max[j]+1);

            }

        }

    }

    int result = 0;

    for(int i=0; i<max.length; i++){

        if(max[i]>result)

            result = max[i];

    }

    return result;

}

public int lengthOfLIS(int[] nums) {

    if(nums==null || nums.length==0)

        return 0;

    ArrayList<Integer> list = new ArrayList<Integer>();

    for(int num: nums){

        if(list.size()==0 || num>list.get(list.size()-1)){

            list.add(num);

        }else{

            int i=0;

            int j=list.size()-1;

            while(i<j){

                int mid = (i+j)/2;

                if(list.get(mid) < num){

                    i=mid+1;

                }else{

                    j=mid;

                }

            }

            list.set(j, num);

        }

    }

    return list.size();

}