Import Java.io.pushback InputStream

package jz.bm; import java.io.PushbackInputStream; import java.lang.reflect.Array; import java.util.ArrayList; import java.util.Arrays; public class bm6 { ArrayList<ArrayList<Integer>> res = new ArrayList<>(); public ArrayList<ArrayList<Integer>> permute(int[] num) { if (num.length == 0) { return res; } Arrays.sort(num); boolean[] used = new boolean[num.length]; Arrays.fill(used, false); dfs(num, used, new ArrayList<>()); return res; } private void dfs(int[] num, boolean[] used,...