使用 MATLAB 进行库存补货（低级 I/O）

Question

又是 I/O 让我感到困惑的时候。在这种情况下，我的目标是编写一个函数，该函数接收一个 .txt 库存项目文件和另一个 .txt 价格文件，并输出补货的总成本，以及一个包含原始库存的 .txt 文件数据和需要补货的物品数量。例如：

Inventory Data:

Buns #50 #63
Burgers #32 #55
Ketchup #6 #10
Hotdogs #4 #35
Mustard #7 #8

注意：标头包含在 .txt 文件中，并且总会有五件商品需要补货

我的输出文件应该是：

Inventory Data:

Buns #50 #63
Burgers #32 #55
Ketchup #6 #10
Hotdogs #4 #35
Mustard #7 #8


Restocking Data:

Buns #63 #13
Burgers #55 #23
Ketchup #10 #4
Hotdogs #35 #31
Mustard #8 #1

我的输出总数应该是 271，因为

Prices:

Buns $2
Burgers $5
Ketchup $1
Hotdogs $4
Mustard $2

Amro 很友善地帮助我弄清楚如何提取我需要的线条，以及如何从我拥有的东西中减去我的需要。现在我的最后一个斗争（也是我在更好地个性化问题之前需要克服的最后一个障碍）是弄清楚如何编写一个输出原始数据以及补充数据的最终数据。它必须看起来像测试用例

 function[restock_cost] = inventory2(file, prices)

%// Reads both files
fh = fopen(file, 'rt');
C = textscan(fh, '%s', 'Delimiter','');
inventory = C{1};
fclose(fh);
Original = C{:};
Original = char(Original);

fh2 = fopen(prices, 'rt');
D = textscan(fh2, '%s', 'Delimiter','');
prices = D{1};
fclose(fh2);

%// Breaks up inventory data
inventory(1) = [];
x = regexp(inventory, '(\w+) #(\d+) #(\d+)', 'tokens', 'once');
x = vertcat(x{:});
itemName = x(:,1);
itemHave = str2double(x(:,2));
itemNeeded = str2double(x(:,3));
itemName = char(itemName);


%// Determines what needs to be restocked and how much is needed
Restock = itemNeeded - itemHave;

%// Breaks up price info
prices(1) = [];
x = regexp(prices, '(\w+) \$(\d+)', 'tokens', 'once');
x = vertcat(x{:});
item = x(:,1);
prices = str2double(x(:,2));

%// Finds the price
restock_cost = sum((Restock .* prices));

%// gets the business name
[name, ~] = strtok(file,'_');

%// Finds the size of Original(may help)
[r,c] = size(Original);
[r2,c2] = size(itemName);
[r3,c3] = size(itemNeeded);

%// Starts to write my output file.
fh2 = fopen([name '_RestockingData.txt'], 'wt');
fprintf(fh2, 'Inventory Data: \n');
fprintf(fh2, '\n');

for i = 2:r %// Don't want the header included
    fprintf(fh2, Original(i,1:c));
    fprintf(fh2,'\n');
end
fprintf(fh2, '\n');
fprintf(fh2,'\n');
fprintf(fh2, 'Restocking Data: \n');
fprintf(fh2,'\n');

for j = 1:r2
    fprintf(fh2, itemName(j,1:c2));
    fprintf(fh2,' #%d ', itemNeeded(j));
    fprintf(fh2, '#%d', Restock(j));
    fprintf(fh2,'\n');
end

end

这很接近，但我需要它来输出进货数据，在项目名称和数字之间只有一个空格。相反，它给了我：

Inventory Data: 

Chips #40 #100    
Lettuce #80 #90   
Cheese #22 #60    
Tortillas #65 #100
Tomatoes #40 #70  



Restocking Data: 

Chips     #100 #60
Lettuce   #90 #10
Cheese    #60 #38
Tortillas #100 #35
Tomatoes  #70 #30

我也试过这个：

Restock_Data = {};
Restock_Data = [Restock_Data, {itemName, itemNeeded, Restock}];
Restocking = {Restock_Data};
Kill_Cell = [{Restocking}];

for j = 1:r2

    fprintf(fh2, Restock_Data(j));
    fprintf(fh2,'\n');
end

我需要将我的单元格转换为其他形式，但索引它（正如您在 Kill_Cell 中看到的那样）不起作用。 结束

这应该就是一切。以下是给我的笔记，以防万一：

Notes: 
   - All inventory numbers will have a # in front of them 
   - All the prices will have a $ in front of them and will always be a
     full dollar amount.
   - When creating the new output every item should be seperated by a space
       Ex. 'Chips #5 #2'
   - There will always be 5 items to stock.
   - If your output file is not EXACTLY the same as the solution txt file,
     then you will receive 0 credit for it.

Answer 1

这是使用 textscan 读取库存文件的一种方法：

fid = fopen('inventory.txt', 'rt');
C = textscan(fid, '%s #%d #%d', 'HeaderLines',1, 'CollectOutput',true);
fclose(fid);

解析的数据：

>> C
C = 
    {5x1 cell}    [5x2 int32]

>> C{1}
ans = 
    'Buns'
    'Burgers'
    'Ketchup'
    'Hotdogs'
    'Mustard'

>> C{2}
ans =
          50          63
          32          55
           6          10
           4          35
           7           8

---

您也可以将文件简单地读取为字符串行的单元阵列（我在之前对您的问题的回答中使用过这个）：

fid = fopen('inventory.txt', 'rt');
C = textscan(fid, '%s', 'Delimiter','');
C = C{1};
fclose(fid);

本例的结果：

>> C
C = 
    'Inventory Data:'
    'Buns #50 #63'
    'Burgers #32 #55'
    'Ketchup #6 #10'
    'Hotdogs #4 #35'
    'Mustard #7 #8'

---

编辑：

就像我展示的那样，首先我们将文件读取为字符串（文本行）的元胞数组：

% read both files
fid = fopen('inventory.txt', 'rt');
C = textscan(fid, '%s', 'Delimiter','');
inventory = C{1};
fclose(fid);

fid = fopen('prices.txt', 'rt');
C = textscan(fid, '%s', 'Delimiter','');
prices = C{1};
fclose(fid);

接下来我们使用正则表达式来匹配文本中的模式：

% parse inventory data
inventory(1) = [];
x = regexp(inventory, '(\w+) #(\d+) #(\d+)', 'tokens', 'once');
x = vertcat(x{:});
itemName = x(:,1)
itemHave = str2double(x(:,2))
itemNeeded = str2double(x(:,3))

% parse prices data
prices(1) = [];
x = regexp(prices, '(\w+) \$(\d+)', 'tokens', 'once');
x = vertcat(x{:});
item = x(:,1)
price = str2double(x(:,2))

最后，您可以应用您的逻辑来补充库存，并打印所需的输出...