void PlaceQueen(int n, int row, int* columns, Solutions* solutions, int* returnSize)
{
if (row == n)
{
pushBack(solutions, columns);
*returnSize = solutions->size;
}
else
{
for (int col = 0; col != n; ++col)
{
if (CheckIfValid(columns, row, col))
{
columns[row] = col;
PlaceQueen(n, row + 1, columns, solutions, returnSize);
}
}
}
}
int PlaceQueens(int** chessboard, int size, int level)
{
count++;
int Q_placed = 0; /*
Q_placed is a flag reflecting that whether a Queen
is placed on the current level or not.
This value is returned to preceeding levels.
*/
int QNextLevel; /*
QNextLevel is a flag reflecting that whether a Queen
is placed on the next level or not.
During recurssion this Flag will allow recurssion
*/
int flag; /*
Determines whether a Queen can be placed at current
position or not.
*/
int i;
for (i = 0; i < size; i++)
{
/*Breaks the loops after all the Queens have been placed*/
if (Q_placed == 1)
break;
/*Check whether Queen can be placed or not*/
flag = CheckKill(chessboard, size, level, i);
/*If Queen can be placed*/
if (flag == 0)
{
/*Queen Placed. This will be changed if Next level Queen is
not placed succesfully*/
Q_placed = 1;
/*Queen Placed. */
chessboard[level][i] = 1;
PlaceQueen(level, i);
/*Check for Last level*/
if (level == size - 1)
;
else /*Place a next level Queen*/
{
QNextLevel = PlaceQueens(chessboard, size, level + 1);
/*If next level Queen is not Placed.*/
if (QNextLevel == 0)
{
/*Mark this level Queen as Not Placed*/
Q_placed = 0;
chessboard[level][i] = 0;
RemoveQueen(level, i);
if (i == size - 1)
HomeQueen(level);
}
}
}
else if (flag == 1)
{
PlaceQueen(level, i);
RemoveQueen(level, i);
if (i == size - 1)
HomeQueen(level);
}
}
return Q_placed;
}
