max subarray

Author: nowrobin

maximum-subarray/nowrobin.js

@@ -0,0 +1,25 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var maxSubArray = function(nums) {
+    if (!nums || nums.length === 0) {
+        return 0;
+    }
+
+    // max_so_far: overall maximum sum
+    let max_so_far = nums[0];
+    
+    // max_ending_here: max sum of subarray ending at current position
+    let max_ending_here = nums[0];
+
+    for (let i = 1; i < nums.length; i++) {
+        // Core decision: start new or extend previous
+        max_ending_here = Math.max(nums[i], max_ending_here + nums[i]);
+
+        // Update overall maximum
+        max_so_far = Math.max(max_so_far, max_ending_here);
+    }
+
+    return max_so_far;
+};