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Dinamic array

Romanoffff (5)
int n = 10;

double *t=new double[n];

for (int i = 0; i < n; ++i)
{
t[i]=1e2;

}

I'm trying to create a dinamic array. But, when I run this code not in the main programm, but in function, array is create, but it has only one double value t[0].
What should I do to make my programm work properly?
Moschops (7244)
What value does t[1] have after you've made the array as above?
Last edited on
Romanoffff (5)
t[1], doesn`t have any values. This program should create array with lenght 10, but it creates only one cell. I can send you all progect, if it will help. Or I can send picture, shows resalts of debagging.
Moschops (7244)
How do you know it only made one double object? Post a bit more code.
Romanoffff (5)
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#include "widget.h"
#include "ui_widget.h"
#include <QTextEdit>
#include <QFileDialog>
#include <QTextStream>
#include <QList>
#include <math.h>
#include <new>
using namespace std;

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    QObject::connect(ui->open_file,SIGNAL(clicked()),this,SLOT(openfile()));
    QObject::connect(ui->flip_button,SIGNAL(clicked()),this,SLOT(flip()));
}

Widget::~Widget()
{
    delete ui;
}

void Widget::changeEvent(QEvent *e)
{
    QWidget::changeEvent(e);
    switch (e->type()) {
    case QEvent::LanguageChange:
        ui->retranslateUi(this);
        break;
    default:
        break;
    }
}

bool test(QList< QList<double> > columns)
{
    int n = 10;


            double *t=new double[n];

            for (int i = 0; i < n; ++i)
                    {
                t[i]=1e2;

                    }

    return true;
}

void diag(QList< QList<double> > &columns)
{

    for(int k=0;k<columns.size();k++)
    {
        for(int i=1+k;i<columns.size();i++)
        {
            double div=columns[i][k]/columns[k][k];

            for(int j=k;j<(columns[0].size());j++)
            {
                 columns[i][j]=columns[i][j]-columns[k][j]*div;
                 if(fabs(columns[i][j])<fabs(-1e-10)) columns[i][j]=0;
            }

        }
    }

}

void Widget::openfile()
{
    QString filename=QFileDialog::getOpenFileName(this,tr("Open Matrix"), "/home", tr("Text Files (*.txt *.dat)"));
    ui->open_file_line->setText(filename);
}
void Widget::flip()
{
    QString filename=ui->open_file_line->text();
    QFile file(filename);
         if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
             return;
         QTextStream in(&file);
         int j=0;
         int i=1;
         int z=ui->spinBox->value();
         QList<double> strings;
         QList< QList<double> > columns;
         QString k="digit:";
         while (!in.atEnd()) {
             j++;
             QString line = in.readLine();
            char * temp_char = new char [line.size()+1];
             QByteArray ba = line.toAscii();
                const char* c_str2 = ba.data();
                strcpy (temp_char, c_str2);
                char * n;
                 n=strtok(temp_char," ");
             columns << strings;
               while(n != NULL)
                {
                 k.append(" ");
                 k.append(n);
                 double numb=atof(n);
                 int str=j-1;
                 columns[str].append(numb);
                         i++;
                 n=strtok(NULL," ");
               }

            delete [] temp_char;
         }
            char bufer[250]={0};
            int summ=5*((i-1)/(j-1))+(j-2)*3;
            char bufer2[100]={0};
            char prec[1]={0};
         int count,count2,shift=0;
         int l=((i-1)/(j));
         sprintf(prec,"%d",z);
         QString result;
          diag(columns);
          int sum2=0;
          for(summ=0;summ<j;summ++)
          {
           for(sum2=0;sum2<l;sum2++)
              {
               QTextStream(&result)<<columns[summ][sum2];
                   if(sum2!=(l-1))
                       QTextStream(&result) <<' ';
              }
            QTextStream(&result) <<'\n';
          }
          if(test(columns)==true)
          {
              QTextStream(&result) <<'\n';
              QTextStream(&result) << "Matrica sovmestna!";
          }
          else
          {
              QTextStream(&result) <<'\n';
              QTextStream(&result) << "Matrica nesovmestna!";
          }
          ui->textEdit->setText(result);

         memset(bufer,'\0',sizeof(bufer));
         memset(bufer2,'\0',sizeof(bufer2));
         for(i=0;i<columns.size();i++)
         columns[i].clear();
         columns.clear();
         strings.clear();
         file.close();
}


I saw it in debugging mode. As you see in "void Widget::flip()" dinamic char array is creating perfectly. But when I try to create it in function, I have problems.

My program make matrix like this:
1 1 1 3
0 1 0 1
0 0 -2 -2
0 0 0 0
from matrix like this:
1 1 1 3
2 3 2 7
3 1 1 5
5 -1 -1 3
And put it to textEdit.
Romanoffff (5)
I`ve found the error!)
In debagging mode the array is displayed like one element t[0][0] instead of number of elements in array, like it happened with the QList of QList.

I`ve found elements of the array with the following construction:

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int a1=t[0][0];
            int a2=t[1][0];
            int a3=t[2][0];
            int a4=t[3][0];
            int a5=t[0][1];
            int a6=t[1][1];
            int a7=t[2][1];
            int a8=t[3][1];
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