Add solution #1648

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,447 LeetCode solutions in JavaScript
+# 1,448 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -1270,6 +1270,7 @@
 1643|[Kth Smallest Instructions](./solutions/1643-kth-smallest-instructions.js)|Hard|
 1646|[Get Maximum in Generated Array](./solutions/1646-get-maximum-in-generated-array.js)|Easy|
 1647|[Minimum Deletions to Make Character Frequencies Unique](./solutions/1647-minimum-deletions-to-make-character-frequencies-unique.js)|Medium|
+1648|[Sell Diminishing-Valued Colored Balls](./solutions/1648-sell-diminishing-valued-colored-balls.js)|Medium|
 1657|[Determine if Two Strings Are Close](./solutions/1657-determine-if-two-strings-are-close.js)|Medium|
 1668|[Maximum Repeating Substring](./solutions/1668-maximum-repeating-substring.js)|Easy|
 1669|[Merge In Between Linked Lists](./solutions/1669-merge-in-between-linked-lists.js)|Medium|

solutions/1648-sell-diminishing-valued-colored-balls.js

@@ -0,0 +1,66 @@
+/**
+ * 1648. Sell Diminishing-Valued Colored Balls
+ * https://leetcode.com/problems/sell-diminishing-valued-colored-balls/
+ * Difficulty: Medium
+ *
+ * You have an inventory of different colored balls, and there is a customer that wants orders
+ * balls of any color.
+ *
+ * The customer weirdly values the colored balls. Each colored ball's value is the number of balls
+ * of that color you currently have in your inventory. For example, if you own 6 yellow balls,
+ * the customer would pay 6 for the first yellow ball. After the transaction, there are only 5
+ * yellow balls left, so the next yellow ball is then valued at 5 (i.e., the value of the balls
+ * decreases as you sell more to the customer).
+ *
+ * You are given an integer array, inventory, where inventory[i] represents the number of balls of
+ * the ith color that you initially own. You are also given an integer orders, which represents
+ * the total number of balls that the customer wants. You can sell the balls in any order.
+ *
+ * Return the maximum total value that you can attain after selling orders colored balls. As the
+ * answer may be too large, return it modulo 109 + 7.
+ */
+
+/**
+ * @param {number[]} inventory
+ * @param {number} orders
+ * @return {number}
+ */
+var maxProfit = function(inventory, orders) {
+  const MOD = 1e9 + 7;
+  inventory.sort((a, b) => b - a);
+  inventory.push(0);
+
+  let totalProfit = 0;
+  let currentColor = 0;
+  let ballsSold = 0;
+
+  while (ballsSold < orders) {
+    const currentCount = inventory[currentColor];
+    const nextCount = inventory[currentColor + 1];
+    const colors = currentColor + 1;
+    const ballsToSell = Math.min(
+      orders - ballsSold,
+      colors * (currentCount - nextCount)
+    );
+
+    const fullSets = Math.floor(ballsToSell / colors);
+    const remainder = ballsToSell % colors;
+
+    if (fullSets > 0) {
+      const endValue = currentCount - fullSets + 1;
+      let sequenceSum = (BigInt(colors) * BigInt(fullSets) % BigInt(MOD))
+        * (BigInt(currentCount) + BigInt(endValue)) % BigInt(MOD);
+      sequenceSum = (sequenceSum * BigInt(500000004)) % BigInt(MOD);
+      totalProfit = (totalProfit + Number(sequenceSum)) % MOD;
+    }
+
+    if (remainder > 0) {
+      totalProfit = (totalProfit + (remainder * (currentCount - fullSets)) % MOD) % MOD;
+    }
+
+    ballsSold += ballsToSell;
+    currentColor++;
+  }
+
+  return totalProfit;
+};