LeetCode 1418. 点菜展示表（哈希map）

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 * 10^4
orders[i].length == 3
1 <= customerNamei.length, foodItemi.length <= 20
customerNamei 和 foodItemi 由大小写英文字母及空格字符 ' ' 组成。
tableNumberi 是 1 到 500 范围内的整数。

class Solution {
public:
    vector<vector<string>> displayTable(vector<vector<string>>& orders) {
        unordered_map<string,map<string,int>> m;//桌号，菜，数量
        vector<vector<string>> food = {{"Table"}};//表头
        vector<string> tableId;//桌号
        for(auto& od : orders)
        {
        	m[od[1]][od[2]]++;
        	tableId.push_back(od[1]);//桌号
        	food[0].push_back(od[2]);//菜品
        }
        sort(tableId.begin(), tableId.end(),[&](auto a, auto b){
            if(a.size()==b.size())
                return a < b;
            return a.size() < b.size();
        });//桌号排序
        tableId.erase(unique(tableId.begin(),tableId.end()), tableId.end());
        //桌号去重
        sort(food[0].begin()+1, food[0].end());
        //菜品排序
        food[0].erase(unique(food[0].begin()+1, food[0].end()), food[0].end());
        //菜品去重
        food.resize(tableId.size()+1);//开辟空间
        for(int i = 1; i < food.size(); ++i)
        {
        	food[i].push_back(tableId[i-1]);//第一列，桌号
        	for(int j = 1; j < food[0].size(); ++j)
        		food[i].push_back(to_string(m[food[i][0]][food[0][j]]));
        		//其余列数量
        }
        return food;
    }
};