add: FindAllSubsets

Author: Jer3myYu

java/Backtracking/FindAllSubsets.java

@@ -0,0 +1,27 @@
+import java.util.ArrayList;
+import java.util.List;
+
+public class FindAllSubsets {
+    public List<List<Integer>> findAllSubsets(int[] nums) {
+        List<List<Integer>> res = new ArrayList<>();
+        backtrack(0, new ArrayList<>(), nums, res);
+        return res;
+    }
+
+    private void backtrack(int i, List<Integer> currSubset, int[] nums, List<List<Integer>> res) {
+        // Base case: if all elements have been considered, add the
+        // current subset to the output.
+        if (i == nums.length) {
+            res.add(new ArrayList<>(currSubset));
+            return;
+        }
+        // Include the current element and recursively explore all paths
+        // that branch from this subset.
+        currSubset.add(nums[i]);
+        backtrack(i + 1, currSubset, nums, res);
+        // Exclude the current element and recursively explore all paths
+        // that branch from this subset.
+        currSubset.remove(currSubset.size() - 1);
+        backtrack(i + 1, currSubset, nums, res);
+    }
+}