About an indefinite matrix

Hi to All,

I need to fill a matrix as this:

Code:

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char mat [N] [N]

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N is an integer, that I don't know.
In my program I have a construct for its Input as this.

Code:

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cin >> N;

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Can work this scenario ?

For Example can work this program?

Code:

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#include <iostream.h>
 
int main()
{
  int N;  /max element for Matrix
  char mat[N][N];
  int i, j; /Counters
 
  cout << 'Enter the number of Rows and Colums ';
  cin >> N;
  cout << endl;
 
  cout << 'Enter the Matrix elements ' << endl;
 
  for (i=0; i<N; i++)
  {
  for (j=0; j<N; j++)
  cout << mat[i][j];
      cout << endl;
  }
  cout << endl;
 
}

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This code is correct ? How can resolve my problem ?

Thank you for help. Be patient with me; I am new in c++ programming.

Best Regards

1. use <iostream>
2. use vector of vectors
3. Check value entered by the user before using it
4. Don't use variables without initializing them

Quote:

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Originally Posted by vart

2. use vector of vectors

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Hi,
Thank You for fast reply.
Please, what is vector of vectors ?
Have You a sample or a link, in order to learn this concept ?

Best Regards

Quote:

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Please, what is vector of vectors ?

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In your context, it would be:

Code:

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std::vector<std::vector<char> > mat;

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You would need to #include <vector>, of course.

If you still want to use your char array you must make it dynamic otherwise your compiler expects a constant.
For example:

Code:

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cin >> N;
char** mat = new char*[N];
for(int i=0;i<N;i++)
    mat[i] = new char[N];

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