feat: add Maximum Product Subarray

Author: dukeluo

README.md

@@ -87,6 +87,7 @@ Roadmap: https://neetcode.io/roadmap
 | 647  | [Palindromic Substrings](https://leetcode.com/problems/palindromic-substrings/description/)                                                                       | Medium     | [ts](./TypeScript/647.palindromic-substrings.ts)                                              | 1-D DP           |
 | 91   | [Decode Ways](https://leetcode.com/problems/decode-ways/description/)                                                                                             | Medium     | [ts](./TypeScript/91.decode-ways.ts)                                                          | 1-D DP           |
 | 300  | [Longest Increasing Subsequence](https://leetcode.com/problems/longest-increasing-subsequence/description/)                                                       | Medium     | [ts](./TypeScript/300.longest-increasing-subsequence.ts)                                      | 1-D DP           |
+| 152  | [Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/description/)                                                                   | Medium     | [ts](./TypeScript/152.maximum-product-subarray.ts)                                            | 1-D DP           |
 
 ### Others
 

TypeScript/152.maximum-product-subarray.ts

@@ -0,0 +1,21 @@
+function maxProduct(nums: number[]): number {
+  let result = nums[0];
+  let currentMax = nums[0];
+  let currentMin = nums[0];
+
+  for (let i = 1; i < nums.length; i++) {
+    const temp = currentMax;
+
+    currentMax = Math.max(temp * nums[i], currentMin * nums[i], nums[i]);
+    currentMin = Math.min(temp * nums[i], currentMin * nums[i], nums[i]);
+
+    if (currentMax > result) {
+      result = currentMax;
+    }
+  }
+
+  return result;
+}
+
+console.log(maxProduct([2, 3, -2, 4]));
+console.log(maxProduct([-2, 0, -1]));