Question

请帮我多维向量。我有一个csv文件。我想要的是它会：

读取csv文件，将其放在6行7列的向量中。
返回矢量。
所有这些都放在一个函数中。不是主要功能。

即使是简单的示例代码也可以。

我最终得到了这个，但我卡住了。

vector< vector <string> > THIRDSTEP::DispSched(string movies)
{
    ifstream file("sched1.csv");
    vector < vector<string> > data(7, vector<string>(6));
    while (!file.eof())
    {
        for (int r = 0; r < 7; ++r)
        {
            vector<string> row;
            string line;
            getline(file, line);
            if (!file.good())
                break;
            stringstream iss(line);

            for (int c = 0; c < 7; ++c)
            {
                string val;
                getline(iss, val, ',');
                if (!iss.good())
                    break;

                stringstream convert(val);
                data.push_back(convert);
            }
        }

    }

    return data;
}

Answer 1

尝试将while循环更改为以下内容：

string line;
int r = 0;

// We can build the vector dynamically. No need to specify the length here.
vector < vector<string> > data;

// while r < 7 and getline gives correct result
while (r < 7 && getline(file, line))
{
        vector<string> row;
        stringstream iss(line);
        int c = 0;
        string val;

        // while c < 7 and getline gives correct result
        while (c < 7 && getline(iss, val, ','))
        {            
            // no need for converting as you are reading string.
            row.push_back(val);
        }
        data.push_back(row);
}

Answer 2

你非常接近。尝试以下几点修改：

vector< vector <string> > THIRDSTEP::DispSched(string movies)
{
    ifstream file("sched1.csv");    
    vector < vector<string> > data(7, vector<string>(6));
    // Clear the array since the rows will be initialized with empty string vectors
    data.clear();
    while (!file.eof())
    {
        for (int r = 0; r < 7; ++r)
        {
            vector<string> row;
            string line;
            getline(file, line);
            if (!file.good())
                break;
            stringstream iss(line);

            for (int c = 0; c < 7; ++c)
            {
                string val;
                getline(iss, val, ',');
                if (!iss.good())
                    break;
                // Not needed, since you only need the one value
                //stringstream convert(val);
                row.push_back(val);
            }
            // Since you've built the columns, add the row
            data.push_back(row); 
        }

    }

    return data;
}

多维向量和csv文件

2 个答案: