Combination Sum

Author: Sunjae95

combination-sum/sunjae95.js

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+/**
+ * @description
+ * brainstorming:
+ * dfs
+ *
+ * time complexity: O(n^k)
+ * space complexity: O(n)
+ */
+var combinationSum = function (candidates, target) {
+  const answer = [];
+
+  const dfs = (array, sum, index) => {
+    if (sum > target) return;
+    if (sum === target) return answer.push(array);
+
+    for (let i = index; i < candidates.length; i++) {
+      const nextArray = array.concat(candidates[i]);
+      const nextSum = sum + candidates[i];
+
+      dfs(nextArray, nextSum, i);
+    }
+  };
+
+  candidates.forEach((value, i) => dfs([value], value, i));
+
+  return answer;
+};