“This is the 15th day of my participation in the Gwen Challenge in November. Check out the details: The Last Gwen Challenge in 2021.”

describe

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.

Example 1:

Input: orders = [["David","3","Ceviche"],["Corina","10","Beef Burrito"],["David","3","Fried Chicken"],["Carla","5","Water"],["Carla","5","Ceviche"],["Rous","3","Ceviche"]]
Output: [["Table","Beef Burrito","Ceviche","Fried Chicken","Water"],["3","0","2","1","0"],["5","0","1","0","1"],["10","1","0","0","0"]] 
Explanation:
The displaying table looks like:
Table,Beef Burrito,Ceviche,Fried Chicken,Water
3    ,0           ,2      ,1            ,0
5    ,0           ,1      ,0            ,1
10   ,1           ,0      ,0            ,0
For the table 3: David orders "Ceviche" and "Fried Chicken", and Rous orders "Ceviche".
For the table 5: Carla orders "Water" and "Ceviche".
For the table 10: Corina orders "Beef Burrito". 
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Example 2:

Input: orders = [["James","12","Fried Chicken"],["Ratesh","12","Fried Chicken"],["Amadeus","12","Fried Chicken"],["Adam","1","Canadian Waffles"],["Brianna","1","Canadian Waffles"]]
Output: [["Table","Canadian Waffles","Fried Chicken"],["1","2","0"],["12","0","3"]] 
Explanation: 
For the table 1: Adam and Brianna order "Canadian Waffles".
For the table 12: James, Ratesh and Amadeus order "Fried Chicken".
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Example 3:

Input: orders = [["Laura","2","Bean Burrito"],["Jhon","2","Beef Burrito"],["Melissa","2","Soda"]]
Output: [["Table","Bean Burrito","Beef Burrito","Soda"],["2","1","1","1"]]
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Note:

  • 1 <= orders.length <= 5 * 10^4
  • orders[i].length == 3
  • 1 <= customerNamei.length, foodItemi.length <= 20
  • customerNamei and foodItemi consist of lowercase and uppercase English letters and the space character.
  • tableNumberi is a valid integer between 1 and 500.

parsing

Given an array of orders, this represents the order placed by a customer at a restaurant. The orders [I] = [customerNamei tableNumberi, foodItemi] customerNamei is the customer’s name, tableNumberi is a customer’s table, foodItemi is project of customer orders.

We are asked to return the display table of a restaurant. “Display table” is a table where the first row is a table header, the first column is “table”, and the remaining columns are arranged alphabetically for each food item. Starting in the second line is the quantity of each food item ordered for each table. It is important to note that the customer name is not part of the table. Rows should also be sorted in ascending order.

It looks like the topic is complicated, in fact, the customer name is useless, the key is to see the table number and the name of the dish, see the example a basic can know the topic requirements, the idea is also relatively simple:

  • Initializing the empty list result: initializing the empty list head: initializing the empty list head: initializing the empty dictionary D: initializing the dishes corresponding to each table number and the number
  • Go through all the orders, record the table number, corresponding dishes and the number of dishes with D, and put the dish name in the head without repetition
  • At the end of the walk, the head is sorted lexicographically and the ‘Table’ string is inserted to the front to form the final header, and head is appended to result
  • Select table d, table d, table D, table D, table D, table D, table D, table D, table D, table D, table D
  • Return result at the end of the loop

answer

class Solution(object):
    def displayTable(self, orders):
        """
        :type orders: List[List[str]]
        :rtype: List[List[str]]
        """
        result = []
        head = []
        d = {}
        for order in orders:
            if order[1] not in d:
                d[order[1]] = {}
            if order[2] not in d[order[1]]:
                d[order[1]][order[2]] = 1
            else:
                d[order[1]][order[2]] += 1
            if order[2] not in head:
                head.append(order[2])
        head.sort()
        head = ['Table'] + head
        result.append(head)
        d = sorted(d.items(), key=lambda d: int(d[0]))
        for k, v in d:
            row = [k]
            for food in head[1:]:
                if food not in v:
                    row.append('0')
                else:
                    row.append(str(v[food]))
            result.append(row)
        return result
        
        	      
		
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The results

Runtime: In the linked list, the molecular weight of each node in the linked list is given in the linked list. Submissions in Python online submissions for Display Table of Food Orders in a Restaurant.Copy the code

Original link: leetcode.com/problems/di…

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