add Maximum Subarray solution

Author: HoonDongKang

maximum-subarray/HoonDongKang.ts

@@ -0,0 +1,36 @@
+/**
+ * [Problem]: [53] Maximum Subarray
+ *
+ * (https://leetcode.com/problems/maximum-subarray/description/)
+ */
+
+function maxSubArray(nums: number[]): number {
+    //시간복잡도 O(n)
+    //공간복잡도 O(1)
+    function getMax(nums: number[]): number {
+        let result = nums[0];
+        let sum = 0;
+
+        nums.forEach((num) => {
+            sum = Math.max(num, sum + num);
+            result = Math.max(sum, result);
+        });
+
+        return result;
+    }
+
+    //시간복잡도 O(n)
+    //공간복잡도 O(1)
+    function dpFunc(nums: number[]): number {
+        const dp = Array(nums.length).fill(0);
+        dp[0] = nums[0];
+
+        for (let i = 1; i < nums.length; i++) {
+            dp[i] = Math.max(nums[i], dp[i - 1] + nums[i]);
+        }
+
+        return Math.max(...dp);
+    }
+
+    return dpFunc(nums);
+}