Question

您好我需要检查我的代码，因为它对我的分段错误。这是因为我的2D矢量没有分配内存，但我该怎么做呢？

std::vector <std::vector <std::string>> pdf_report::random_data (int num_entries, int report_type)
{
    std::vector <std::vector <std::string>> printer_control;
    int card_num_max = 999899, card_num_min = 100000;   // card number
    int vol_ent_max = 1000, vol_ent_min = 10;   // volume entered
    int vol_disp_max = 7, vol_disp_min = 0; // volume dispensed
    int cn_type_max = 10, cn_type_min = 1;  // card type
    int charge_amt_max = 400, charge_amt_min = 2;
    int vol_bal_max = 6000, vol_bal_min = 0;
    int auth_num_max = 9999, auth_num_min = 1000;
    srand (time (NULL));    // seed rand () with new values

    switch (report_type)
    {
        case 1: // Report 1: Card Number, Volume Entered, Volume Dispensed
        {
            // fill a string array with random values
            for (int k = 0; k < num_entries; k++) 
            {
                int randNum = 0;
                int randNum1 = 0;
                int randNum2 = 0;
                int randNum3 = 0;

                // fill column 0 for Card Number
                randNum = rand() % (card_num_max - card_num_min) + card_num_min;    // generate random numbers inside range
                printer_control [k][0] = int_to_str (randNum);  // set string array element equal to converted int

                // fill column 1 for Volume Entered
                randNum1 = rand() % (vol_ent_max - vol_ent_min) + vol_ent_min;  // generate random numbers inside range
                printer_control [k][1] = int_to_str (randNum1); // set string array element equal to converted int

                // fill column 2 for Volume Dispensed
                randNum2 = rand() % (vol_disp_max - vol_disp_min);  // generate random numbers inside range
                randNum3 = randNum1 - randNum2; // volume dispensed could be lower than the number entered, but not higher
                printer_control [k][2] = int_to_str (randNum3); // set string array element equal to converted int
            }   
            break;
        }
    }

    return printer_control;
}

我有更多的案例，但只需要一个工作就是我需要复制给其他人。谢谢您的帮助。

Answer 1

从您的代码中，我假设printer_control是num_entries x 3的矩阵。

要初始化vector<vector<string> >，请执行以下操作：

printer_control.resize (num_entries);
for (int i=0; i<num_entries; i++)
   printer_control[i].resize (3);

C ++，2D矢量分割故障

1 个答案: