diff --git a/combination-sum/HerrineKim.js b/combination-sum/HerrineKim.js
new file mode 100644
index 000000000..4549f6f24
--- /dev/null
+++ b/combination-sum/HerrineKim.js
@@ -0,0 +1,30 @@
+// 시간 복잡도 : O(n^2)
+// 공간 복잡도 : O(n)
+
+/**
+ * @param {number[]} candidates
+ * @param {number} target
+ * @return {number[][]}
+ */
+
+var combinationSum = function(candidates, target) {
+  const result = [];
+  
+  const backtrack = (remaining, combo, start) => {
+      if (remaining === 0) {
+          result.push([...combo]);
+          return;
+      }
+      
+      for (let i = start; i < candidates.length; i++) {
+          if (candidates[i] <= remaining) {
+              combo.push(candidates[i]);
+              backtrack(remaining - candidates[i], combo, i);
+              combo.pop();
+          }
+      }
+  };
+  
+  backtrack(target, [], 0);
+  return result;
+};
diff --git a/maximum-subarray/HerrineKim.js b/maximum-subarray/HerrineKim.js
new file mode 100644
index 000000000..87ed8199c
--- /dev/null
+++ b/maximum-subarray/HerrineKim.js
@@ -0,0 +1,18 @@
+// 시간 복잡도 : O(n)
+// 공간 복잡도 : O(1)
+
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var maxSubArray = function(nums) {
+  let currentSum = nums[0];
+  let maxSum = nums[0];
+
+  for (let i = 1; i < nums.length; i++) {
+      currentSum = Math.max(nums[i], currentSum + nums[i]);
+      maxSum = Math.max(maxSum, currentSum);
+  }
+
+  return maxSum;
+};
diff --git a/two-sum/HerrineKim.js b/two-sum/HerrineKim.js
new file mode 100644
index 000000000..595c2898b
--- /dev/null
+++ b/two-sum/HerrineKim.js
@@ -0,0 +1,22 @@
+// 시간 복잡도 : O(n)
+// 공간 복잡도 : O(n)
+
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number[]}
+ */
+var twoSum = function(nums, target) {
+  let numMap = new Map();
+  
+  for (let i = 0; i < nums.length; i++) {
+      let complement = target - nums[i];
+      
+      if (numMap.has(complement)) {
+          return [numMap.get(complement), i];
+      }
+      
+      numMap.set(nums[i], i);
+  }
+};
+