分配帮助更新特定城市中 "shipments" 和 "orders" 的每个项目的数量

Question

我的作业要求我在名为 "ITEMRECORD.txt" 的文件中创建一个包含记录列表的文件，我在下面有：

    type warehouse amt1 amt2 amt3
    -----------------------------
    s    NewYork    23   14   1
    s    Miami      25   25   25
    s    LosAngeles 40   13   17
    s    Houston    100  30   10
    s    Chicago    42   23   19
    s    NewYork    0    0    15
    s    Miami      13   17   21
    o    LosAngeles 15   10   15
    o    NewYork    12   24   8
    o    Houston    75   45   10
    o    Chicago    20   15   15
    o    NewYork    15   0    0
    s    LosAngeles 10   20   10
    s    Houston    0    30   40
    o    NewYork    15   15   25
    o    Chicago    75   30   40
    s    NewYork    20   15   20
    o    Houston    10   20   10

我能够编写读取每一行文本和数字并区分 "shipments" 和 "orders"

的代码

    #include <iostream>
    #include <iomanip>
    #include <fstream>

    using namespace std;
    ifstream itemRec;

    struct record
    {
        char type;
        string warehouse[5] = {"NewYork", "LosAngeles", "Miami", "Houston",    "Chicago"};
        int amt[3] = {0,0,0};
    };
    struct price {
        double price;
    };

    int main ()
    {
        itemRec.open("ITEMRECORD.txt");
        record records;
        price item[3];

        string city1;
        int amt1, amt2, amt3;

        if(!itemRec)
        {
            cout << "Cannot open the record of items file!! Check file please!" << endl;
        }

        for (int i=0; i<3; i++)
        {
            itemRec >> item[i].price;
        }

        while (itemRec >> records.type)
        {

            if (records.type == 's')                         // READING IN A      SINGLE SHIPMENT CARD
            {       
                itemRec >>  city1;
                for(int i=0; i<5; i++)
                {
                    if (city1 == records.warehouse[i])
                    {
                            itemRec >> records.amt[0];
                            itemRec >> records.amt[1];
                            itemRec >> records.amt[2];
                    }
                }
            cout << records.type <<"\t" << city1 << "\t" << records.amt[0] << "\t" << records.amt[1] << "\t" << records.amt[2] << endl;
            }
            else if (records.type == 'o')                           // READING IN A SINGLE ORDER CARD
            {
                itemRec >>  city1;
                for(int i=0; i<5; i++)
                {
                    if (city1 == records.warehouse[i])
                    {
                            itemRec >> records.amt[0];
                            itemRec >> records.amt[1];
                            itemRec >> records.amt[2];  
                    }
                }
            cout << records.type <<"\t" << city1 << "\t" << records.amt[0] << "\t" << records.amt[1] << "\t" << records.amt[2] << endl;
            }
        }

但是，我遇到问题的部分是，每张卡片都被读入以更新每个仓库中的物品数量。例如，第一行是 s NewYork 23 14 1 当它看到 s NewYork 0 0 15 时，我希望程序将 amt1、amt2、amt3 中的数字分别更新为 23 14 16。

我如何开始编写代码以在找到特定城市时更新这些金额？

Answer 1

无论您找到什么，您都会立即分配它并删除旧值：

if (city1 == records.warehouse[i])
{
    itemRec >> records.amt[0];
    itemRec >> records.amt[1];
    itemRec >> records.amt[2];
}

所以改为这样做：

if (city1 == records.warehouse[i])
{
     itemRec >> temp1; // declare a place holder
     itemRec >> temp2;
     itemRec >> temp3;

     records.amt[0] += temp1; // add the holder's value to the current value
     records.amt[1] += temp2;
     records.amt[2] += temp3;
}

分配帮助更新特定城市中 "shipments" 和 "orders" 的每个项目的数量

Assignment help updating amounts of each item for "shipments" and "orders" in a specific city

c++

orders