78_Subsets.java

classSolution {
publicList<List<Integer>> subsets(int[] nums) {
if (nums == null || nums.length == 0) {
returnCollections.emptyList();
 }

List<List<Integer>> result = newArrayList<>();
dfs(nums, 0, newArrayList<>(), result);
returnresult;
 }

privatevoiddfs(int[] nums, intidx, List<Integer> tempResult, List<List<Integer>> result) {
result.add(newArrayList<>(tempResult));

for (inti = idx; i < nums.length; i++) {
tempResult.add(nums[i]);
dfs(nums, i + 1, tempResult, result);
tempResult.remove(tempResult.size() - 1);
 }
 }
}