Method dfs

src/class136/ShowDetails.java:232–241

(long[] nums, int n, int i, boolean pick, long path, HashSet<Long> set)

	// 当前i位置的数字要或者不要全决策
	// 收集所有可能的异或和
	public static void dfs(long[] nums, int n, int i, boolean pick, long path, HashSet<Long> set) {
		if (i > n) {
			if (pick) {
				set.add(path);
			}
		} else {
			dfs(nums, n, i + 1, pick, path, set);
			dfs(nums, n, i + 1, true, path ^ nums[i], set);
		}
	}

}