WEEK 3 Solutions

Author: juhui-jeong

combination-sum/juhui-jeong.java

@@ -0,0 +1,24 @@
+class Solution {
+    public List<List<Integer>> combinationSum(int[] candidates, int target) {
+        // dfs & 백트래킹
+        List<List<Integer>> resultList = new ArrayList<>();
+        dfs(candidates, target, 0, new ArrayList<>(), resultList);
+        return resultList;
+    }
+    private void dfs(int[] candidates, int target, int start, List<Integer> path, List<List<Integer>> resultList) {
+        if (target == 0) {
+            resultList.add(new ArrayList<>(path));
+            return;
+        }
+
+        if (target < 0) {
+            return;
+        }
+
+        for(int i = start; i < candidates.length; i++) {
+            path.add(candidates[i]);
+            dfs(candidates, target - candidates[i], i, path, resultList);
+            path.remove(path.size() -1);
+        }
+    }
+}