Create 1856-maximum-subarray-min-product.kt

Author: a93a

kotlin/1856-maximum-subarray-min-product.kt

@@ -0,0 +1,33 @@
+class Solution {
+    fun maxSumMinProduct(nums: IntArray): Int {
+        val prefix = LongArray(nums.size + 1)
+        val stack = ArrayDeque<Pair<Int, Long>>()
+        val mod = 1000000007L
+        
+        for (i in nums.indices) {
+            prefix[i + 1] = prefix[i] + nums[i]
+        }
+
+        var res = 0L
+        for ((i, n) in nums.withIndex()) {
+            var start = i
+
+            while (stack.isNotEmpty() && stack.peekLast().second > n) {
+                val (lastStart, value) = stack.removeLast()
+                val total = prefix[i] - prefix[lastStart]
+                res = maxOf(res, total * value)
+                start = lastStart
+            }
+
+            stack.addLast(start to n.toLong())
+        }
+        
+        for ((start, value) in stack) {
+            val total = prefix[nums.size] - prefix[start]
+            res = maxOf(res, total * value)
+        }
+
+
+        return (res % mod).toInt()
+    }
+}