solve(w03): 39. Combination Sum

Author: jeongwoo903

combination-sum/jeongwoo903.js

@@ -0,0 +1,29 @@
+/*
+* k: 후보 수
+* t: target / 최소 숫자
+* 시간 복잡도: O(k^t)
+* 공간 복잡도; O(k^t * t)
+*/
+
+/**
+ * @param {number[]} candidates
+ * @param {number} target
+ * @return {number[][]}
+ */
+
+var combinationSum = function(candidates, target) {
+  const combine = (sum, path, startIndex) => {
+    if (sum > target) return [];
+    if (sum === target) return [path];
+
+    return candidates
+    .slice(startIndex)
+    .flatMap((candidate, i) =>
+      combine(sum + candidate, [...path, candidate], startIndex + i)
+    );
+  };
+
+  return candidates.flatMap((candidate, i) =>
+    combine(candidate, [candidate], i)
+  );
+};