Can't find the error

[TheRedViper]

Hello there, this is a program in windows form based in C that prints the prime numbers within an interval into a label when the button is pressed. The program compiles with no errors but when the button is clicked, the program just freezes. Iv'e rechecked my loop as the typical error would be an infinite loop but I can't seem to find where it breaks up.

 

#pragma endregion
	private: System::Void btnAction_Click(System::Object^  sender, System::EventArgs^  e) {
	
	int iMin = 0, iMax = 0, i =0, iDrapeau = 0;
	
	if(txtEntier1->Text != "")
	{
		if(txtEntier2->Text != "")
		{
			iMin.TryParse(txtEntier1->Text,iMin);
			iMax.TryParse(txtEntier2->Text,iMax);
			
			while(iMin < iMax)
			{
				for(i = 2;i <= iMin/2; ++i)
				{
					if(iMin % i == 0)
					{
						iDrapeau = 1;
						break;
					}
				}
				if(iDrapeau == 0)
				{
					lblNombrePremier->Text += ", " + iMin.ToString();
					iMin++;
				}
			}
		}
		else
		{
			MessageBox::Show("Entre un nombre entier maximum valide!");
		}
	}
	else
	{
		MessageBox::Show("Entre un nombre entier minimum valide!");
	}

}

 

[Mira Yurizaki]

I added comments:

#pragma endregion
	private: System::Void btnAction_Click(System::Object^  sender, System::EventArgs^  e) {
	
	int iMin = 0, iMax = 0, i =0, iDrapeau = 0;
	
	if(txtEntier1->Text != "")
	{
		if(txtEntier2->Text != "")
		{
			iMin.TryParse(txtEntier1->Text,iMin);
			iMax.TryParse(txtEntier2->Text,iMax);
			
			while(iMin < iMax)
			{
				for(i = 2;i <= iMin/2; ++i)
				{
					if(iMin % i == 0)
					{
						iDrapeau = 1;
						break; // This only breaks out of the for loop
					}
				}
				if(iDrapeau == 0)
				{
					lblNombrePremier->Text += ", " + iMin.ToString();
					iMin++; // If iDrapeau is 1, this never gets ran, and so iMin < iMax is always going to be true
                    // And it doesn't appear you have iDrapeau = 0 anywhere else
				}
			}
		}
		else
		{
			MessageBox::Show("Entre un nombre entier maximum valide!");
		}
	}
	else
	{
		MessageBox::Show("Entre un nombre entier minimum valide!");
	}

}

 

[TheRedViper]

1 hour ago, M.Yurizaki said:

I added comments:

#pragma endregion
	private: System::Void btnAction_Click(System::Object^  sender, System::EventArgs^  e) {
	
	int iMin = 0, iMax = 0, i =0, iDrapeau = 0;
	
	if(txtEntier1->Text != "")
	{
		if(txtEntier2->Text != "")
		{
			iMin.TryParse(txtEntier1->Text,iMin);
			iMax.TryParse(txtEntier2->Text,iMax);
			
			while(iMin < iMax)
			{
				for(i = 2;i <= iMin/2; ++i)
				{
					if(iMin % i == 0)
					{
						iDrapeau = 1;
						break; // This only breaks out of the for loop
					}
				}
				if(iDrapeau == 0)
				{
					lblNombrePremier->Text += ", " + iMin.ToString();
					iMin++; // If iDrapeau is 1, this never gets ran, and so iMin < iMax is always going to be true
                    // And it doesn't appear you have iDrapeau = 0 anywhere else
				}
			}
		}
		else
		{
			MessageBox::Show("Entre un nombre entier maximum valide!");
		}
	}
	else
	{
		MessageBox::Show("Entre un nombre entier minimum valide!");
	}

}

 

Thank you, the problem was the iMin++ being inside the flag == 0 instead of outside. Its working now.

 

int iMin = 0, iMax = 0, i, iFlag, iReset = 0, iComma = 0;
    
    iReset++;
	if(txtEntier1->Text != "")
	{
		if(txtEntier2->Text != "")
		{
			if(iMin.TryParse(txtEntier1->Text,iMin))
			{
				if(iMax.TryParse(txtEntier2->Text,iMax))
				{
	
					if(iReset > 0)
					{
						lblNombrePremier->Text = "";
						iReset = 0;
					}
					while (iMin < iMax)
					{
						iFlag = 0;

						for(i = 2; i <= iMin/2; ++i)
						{
							if(iMin % i == 0)
							{
								iFlag = 1;
								break;
							}
						}

						if (iFlag == 0)
						{
							if(iComma == 0)
							{
								lblNombrePremier->Text += iMin.ToString();
								iComma++;
							}
							else
							{
							lblNombrePremier->Text += ", " + iMin.ToString();
							}
						}
						++iMin;
					}
					iComma = 0;
				}
				else
				{
					MessageBox::Show("Entre un nombre entier maximum valide!");
				}
			}
			else
			{
				MessageBox::Show("Entre un nombre entier minimum valide!");
			}
		}
		else
		{
			MessageBox::Show("Entre un nombre entier maximum valide!");
		}
	}
	else
	{
		MessageBox::Show("Entre un nombre entier minimum valide!");
	}