Longest Common Subsequence Between Sorted Arrays

给一个sorted array组, 求所有的lcs.

这题都sorted了, 所以顺序不再重要, 所以就是查这几个array有几个重复的元素.

class Solution {
    public List<Integer> longestCommomSubsequence(int[][] arrays) {
        Set<Integer> set = new HashSet<Integer>();
        for(int i = 0; i < arrays[0].length; i++)
        {
            set.add(arrays[0][i]);
        }
        for(int i = 1; i < arrays.length; i++)
        {
            Set<Integer> set1 = new HashSet<>(); 
            for(int j = 0; j < arrays[i].length; j++)
            {
                set1.add(arrays[i][j]);
            }
            set.retainAll(set1);
        }
        return new ArrayList<>(set);
    }
}