import java.util.*; public class Main { public static boolean dfs(int[][] mat, ArrayList<Integer> iLst, ArrayList<Integer> jLst, int now) { if(now == iLst.size()) { return true; } int i = iLst.get(now), j = jLst.get(now); int x = i / 3, y = j / 3; HashSet<Integer> set = new HashSet...