Add week 4 solutions: maximum-product-subarray

Author: gitsunmin

maximum-product-subarray/gitsunmin.ts

@@ -0,0 +1,21 @@
+/**
+ * https://leetcode.com/problems/maximum-product-subarray
+ * time complexity : O(n)
+ * space complexity : O(1)
+ */
+function maxProduct(nums: number[]): number {
+    let r = nums[0];
+    let mx = 1, mn = 1;
+
+    for (let i = 0; i < nums.length; i++) {
+        const tempMx = mx * nums[i];
+        const tempMn = mn * nums[i];
+
+        mx = Math.max(tempMx, tempMn, nums[i]);
+        mn = Math.min(tempMx, tempMn, nums[i]);
+
+        r = Math.max(r, mx);
+    }
+
+    return r;
+}