8 queens

[AZRebelCowgirl73]

I am trying to develop an 8 queens program, and currently it is working however it is printing 87222211 which is obviously wrong, I am trying to print the row of the queen in order from column0-column7 of an array. I am new to C++ and was wondering if anyone could see my mistake? Thanks for taking a look. Here is my code.

int a[8];
 
void display ();
 
int TestLegal (int currentColumn, int currentRow)
{
	for (int column = 0; column < currentColumn; ++column)	//check row conflict
		if (a[column] == a[currentColumn])	
		return (0);	// return FALSE if both queens are on the same row
	
	for (int column = 0; column < currentColumn; ++column)	//check diagonal conflict
		if (abs(a[column] - column) == (abs(a[currentColumn] - currentColumn)))
		return (0);   // return FALSE if both queens are on the same diagonal.
	return currentRow;
}
 
int placeQueen (int column) {
  if (column == 8)	//Check if all columns have a legal value
  {
    display();
    return (-1);
  }
 
  for (int row = 1; row <= 8; ++row)  // Try all of the legal values for the column
  {
    if (TestLegal (column, row))
    {
      a[column] = row;
      if (placeQueen (column + 1) < 0)
        return -1;
    }
  }
  return (0);
}

[Banfa]

I have removed some of your (non-relevant) code because we forbid posting complete answers to homework questions. I am assuming this is a homework question on the grounds I had to do the same question for homework when I was learning prolog (18 years ago).

To answer you queries

		if (abs(a[column] - column) == (abs(a[currentColumn] - currentColumn)))
		return (0);   // return FALSE if both queens are on the same diagonal.

I do not believe this is correct logic for calculating if 2 queens are on the same diagonal. I suggest you get a chess board and run a few examples using pen and paper.

    if (TestLegal (column, row))
    {
      a[column] = row;
      if (placeQueen (column + 1) < 0)
        return -1;
    }

The call to TestLegal uses a[column] in it's calculations but you do not set a[column] until after the call returns.


a is a very poor name for a variable.