Add solution #1418

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,293 LeetCode solutions in JavaScript
+# 1,294 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -1084,6 +1084,7 @@
 1415|[The k-th Lexicographical String of All Happy Strings of Length n](./solutions/1415-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n.js)|Medium|
 1416|[Restore The Array](./solutions/1416-restore-the-array.js)|Hard|
 1417|[Reformat The String](./solutions/1417-reformat-the-string.js)|Easy|
+1418|[Display Table of Food Orders in a Restaurant](./solutions/1418-display-table-of-food-orders-in-a-restaurant.js)|Medium|
 1422|[Maximum Score After Splitting a String](./solutions/1422-maximum-score-after-splitting-a-string.js)|Easy|
 1431|[Kids With the Greatest Number of Candies](./solutions/1431-kids-with-the-greatest-number-of-candies.js)|Easy|
 1436|[Destination City](./solutions/1436-destination-city.js)|Easy|

solutions/1418-display-table-of-food-orders-in-a-restaurant.js

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+/**
+ * 1418. Display Table of Food Orders in a Restaurant
+ * https://leetcode.com/problems/display-table-of-food-orders-in-a-restaurant/
+ * Difficulty: Medium
+ *
+ * Given the array orders, which represents the orders that customers have done in a restaurant.
+ * More specifically orders[i]=[customerNamei,tableNumberi,foodItemi] where customerNamei is the
+ * name of the customer, tableNumberi is the table customer sit at, and foodItemi is the item
+ * customer orders.
+ *
+ * Return the restaurant's “display table”. The “display table” is a table whose row entries
+ * denote how many of each food item each table ordered. The first column is the table number
+ * and the remaining columns correspond to each food item in alphabetical order. The first row
+ * should be a header whose first column is “Table”, followed by the names of the food items.
+ * Note that the customer names are not part of the table. Additionally, the rows should be
+ * sorted in numerically increasing order.
+ */
+
+/**
+ * @param {string[][]} orders
+ * @return {string[][]}
+ */
+var displayTable = function(orders) {
+  const foodItems = new Set();
+  const tableOrders = new Map();
+
+  for (const [, table, item] of orders) {
+    foodItems.add(item);
+    const tableMap = tableOrders.get(table) || new Map();
+    tableMap.set(item, (tableMap.get(item) || 0) + 1);
+    tableOrders.set(table, tableMap);
+  }
+
+  const sortedItems = [...foodItems].sort();
+  const header = ['Table', ...sortedItems];
+  const result = [header];
+
+  for (const table of [...tableOrders.keys()].sort((a, b) => a - b)) {
+    const row = [table];
+    const items = tableOrders.get(table);
+    for (const item of sortedItems) {
+      row.push(String(items.get(item) || 0));
+    }
+    result.push(row);
+  }
+
+  return result;
+};