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sth. wrong with (maybe) for loop + upper line

AIVIO (43)
Hi!
Again things went wrong and when I was trying to write an IsMagic program,I faced an error.
at line 41 I get a break and error.
(I can't understand the reason)
Let me give an explanation about the program. This gets the numbers of a matrix from the user and adds up the rows and columns and Xs (I don't know what are they in English) and tells if they are the same or not, but when it is going to add up the numbers of a row it breaks.
(VS2010, Win32ConsoleApplication)

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#include <iostream>
#include <conio.h>
using namespace std;

int main()
{
	int a,**m,i,j,n1,n2;
	bool magic=true;
	cout<<"What is the length and width of your square?"<<endl;
	cin>>a;
	cout<<"Now enter these, which are wanted:"<<endl;
	m=new int *[a];
	for (i=0;i<a;i++)
		m[i]=new int [a];
	for (i=1;i<=a;i++)
	{
		for (j=1;j<=a;j++)
		{
			cout<<"M["<<i<<"]"<<"["<<j<<"] :";
			cin>>n1;
			m[i-1][j-1]=n1;
		}
	}
	cout<<"\nThis is your Matrix:\n\n";
	for (i=0;i<a;i++)
	{
		for (j=0;j<a;j++)
		{
			cout<<m[i][j]<<"\t";
		}
		cout<<endl<<endl;
	}
	cout<<"\nand it is ";
	for (i=0;i<a;i++)
	{
		if (i>0)
			n2=n1;
		n1=0;
		for(j=0;j<a;j++)
		{
			n1=n1+m[i][j];
		}
			if (i>0)
			{
				if (n2!=n1)
				{
					magic=false;
					cout<<"not magic.";
					break;
				}
				if (magic==false)
					break;
			}
		if (magic==false)
			break;
	}
	if (magic==true)
	{
		cout<<"magic.";
	}
	cin>>a;
	cout<<"\nPress any key to continue ... ";
	getch();
}


+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
And I have another question:
is there some keyword like endl , but takes the line one level upper? I mean the previous line, not next line???

Thank you in advance and Thanks for answering my earlier Topics.
Last edited on
Peter87 (11175)
Remember that indices starts at zero so your loops should look like for (i=0;i<a;i++)
Last edited on
AIVIO (43)
I changed that + I completed my code.
But things don't work.
Error is: Unhandled exception at 0x0041184e in Tutorial.exe: 0xC0000005: Access violation reading location 0xfdfdfdfd.

(I changed the code in the topic's first post)
Peter87 (11175)
<= should be <.
Last edited on
AIVIO (43)
Thank you!
It is all working fine!
I'll change the code in the first post and close the topic.
Thanks again
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