点菜展示表

leetcode-点菜展示表

题目描述

给你一个数组 orders，表示客户在餐厅中完成的订单，确切地说， orders[i]=[customerName_i,tableNumber_i,foodItem_i] ，其中 customerName_i 是客户的姓名，tableNumber_i 是客户所在餐桌的桌号，而 foodItem_i 是客户点的餐品名称。

请你返回该餐厅的 点菜展示表 。在这张表中，表中第一行为标题，其第一列为餐桌桌号 “Table” ，后面每一列都是按字母顺序排列的餐品名称。接下来每一行中的项则表示每张餐桌订购的相应餐品数量，第一列应当填对应的桌号，后面依次填写下单的餐品数量。

注意：客户姓名不是点菜展示表的一部分。此外，表中的数据行应该按餐桌桌号升序排列。

示例 1：

输入：orders = [["David","3","Ceviche"],["Corina","10","Beef Burrito"],["David","3","Fried Chicken"],["Carla","5","Water"],["Carla","5","Ceviche"],["Rous","3","Ceviche"]]
输出：[["Table","Beef Burrito","Ceviche","Fried Chicken","Water"],["3","0","2","1","0"],["5","0","1","0","1"],["10","1","0","0","0"]]
解释：
点菜展示表如下所示：
Table,Beef Burrito,Ceviche,Fried Chicken,Water
3 ,0 ,2 ,1 ,0
5 ,0 ,1 ,0 ,1
10 ,1 ,0 ,0 ,0
对于餐桌 3：David 点了 "Ceviche" 和 "Fried Chicken"，而 Rous 点了 "Ceviche"
而餐桌 5：Carla 点了 "Water" 和 "Ceviche"
餐桌 10：Corina 点了 "Beef Burrito"
示例 2：

输入：orders = [["James","12","Fried Chicken"],["Ratesh","12","Fried Chicken"],["Amadeus","12","Fried Chicken"],["Adam","1","Canadian Waffles"],["Brianna","1","Canadian Waffles"]]
输出：[["Table","Canadian Waffles","Fried Chicken"],["1","2","0"],["12","0","3"]]
解释：
对于餐桌 1：Adam 和 Brianna 都点了 "Canadian Waffles"
而餐桌 12：James, Ratesh 和 Amadeus 都点了 "Fried Chicken"
示例 3：

输入：orders = [["Laura","2","Bean Burrito"],["Jhon","2","Beef Burrito"],["Melissa","2","Soda"]]
输出：[["Table","Bean Burrito","Beef Burrito","Soda"],["2","1","1","1"]]

提示：

• 1 <= orders.length <= 5 * 10⁴
• orders[i].length == 3
• 1 <= customerName_i.length, foodItem_i.length <= 20
• customerName_i 和 foodItem_i 由大小写英文字母及空格字符 ' ' 组成。
• tableNumber_i 是 1 到 500 范围内的整数。

本人题解

/**
 * @param {string[][]} orders
 * @return {string[][]}
 */
var displayTable = function(orders) {
  let tables = {}, foods = {};
  orders.forEach(o => {
    let tid = o[1], food=o[2], table = tables[tid] || {}
    table[food] = table[food] || 0;
    table[food] ++;
    tables[tid] = table;
    foods[food] = true
  })
  let foodsOrder = Object.keys(foods).sort((a, b) => {
    let i = 0;
    while (a[i] || b[i]) {
      if (a[i] == b[i]) { i++ } 
      else {
        if (!a[i]) { return -1 } 
        else if (!b[i]) { return 1 } 
        else { return a[i] < b[i] ? -1 : 1 }
      }
    }
  })
  foodsOrder.forEach((f, i) => foods[f] = i)
  let result = Object.keys(tables).sort((a, b) => parseInt(a) - parseInt(b)).map(tid => {
    let table = tables[tid], r = Array.from({length: foodsOrder.length}).fill('0');
    Object.keys(table).forEach(f => r[foods[f]] = ''+table[f])
    r.unshift(tid)
    return r
  })
  foodsOrder.unshift('Table')
  result.unshift(foodsOrder)
  return result
};

分析

忘了。以后再补