Add maximum subarray solution

Author: hyunjung-choi

maximum-subarray/hyunjung-choi.kt

@@ -0,0 +1,13 @@
+class Solution {
+    fun maxSubArray(nums: IntArray): Int {
+        var currentSum = nums[0]
+        var maxSum = nums[0]
+
+        for (i in 1 until nums.size) {
+            currentSum = if (currentSum < 0) nums[i] else currentSum + nums[i]
+            maxSum = maxOf(currentSum, maxSum)
+        }
+
+        return maxSum
+    }
+}