C # version of Queen's question (non-recursive)

recursion | problem

/*
*author:junyi Sun @CCNU
* e-mail:fxsjy@yahoo.com.cn
*/

Using System;
Namespace Sunjoy
{
public class Queen
{
public static int Main ()
{
int board_size = 0,x=0,y=0;//Checkerboard size, current line, when front
UINT Solution_count = 0; Number of Queens placement scheme
int[] Rows, cols, slot1, Slot2, x2y;//row occupancy, column occupancy, "/" oblique slash occupancy, "\" diagonal position, queen coordinates
DateTime T_start, T_end;

Console.WriteLine ("Please enter the size of the chessboard");
Try
{
Board_size = Convert.ToInt32 (Console.ReadLine ());
if (board_size <= 0)
{
Console.WriteLine ("Illegal data");
return-1;
}
}
catch (Exception e) {Console.WriteLine ("Occurrence exception" + e.message);

rows = new Int[board_size];
cols = new Int[board_size];
slot1 = new int[board_size * 2-1];
Slot2 = new int[board_size * 2-1];
x2y = new Int[board_size];

for (int i = 0; i < board_size; i++)
X2y[i] =-1; Coordinates are initialized to 1.
T_start = DateTime.Now;
while (true)
{
for (y = x2y[x]+1 y < board_size; y++)
if (rows[x] = = 0 && cols[y] = = 0 && slot1[x + y] = = 0 && slot2[x-y + board_size-1] = = 0)
Break

if (Y < board_size)
{
The pieces in line x fall
ROWS[X] = 1; Cols[y] = 1; Slot1[x + y] = 1; Slot2[x-y + board_size-1] = 1; X2y[x] = y;
}
Else
{
Backtrack, pick up the pieces
if (x > 0)
{
X2Y[X] =-1;
x--;
Rows[x] = 0; COLS[X2Y[X]] = 0; Slot1[x + x2y[x]] = 0; SLOT2[X-X2Y[X] + board_size-1] = 0;
Continue
}
else break;
}
if (x = = board_size-1)//If a set of solutions has been obtained, that is, when the last line of pieces is settled
{
for (int i = 0; i < board_size; i++)
{
for (int j = 0; J < Board_size; J + +)
{
if (x2y[i] = = j) Console.Write ("Q");
else Console.Write ("");
}
Console.Write ("\ n");

}
Console.Write ("\ n");
solution_count++; Total programme number plus one
Rows[x] = 0; COLS[X2Y[X]] = 0; Slot1[x + x2y[x]] = 0; SLOT2[X-X2Y[X] + board_size-1] = 0;//Discard this column

}
Else
{
x + +; Continue with the next line
}
}
T_end = DateTime.Now;
Console.WriteLine ("Total {0} Group solution", Solution_count);
Console.WriteLine ("Calculate and print shared time {0} seconds", T_end-t_start);
return 0;
}
}
}

___________________________________________________________

Test results:
Please enter the size of the chessboard
4
Q
Q
Q
Q

Q
Q
Q
Q

Total 2 groups of solutions
Calculate and print shared time 00:00:00 seconds

_______________________________________________
Please enter the size of the chessboard
6
Q
Q
Q
Q
Q
Q

Q
Q
Q
Q
Q
Q

Q
Q
Q
Q
Q
Q

Q
Q
Q
Q
Q
Q

Total 4 groups of solutions
Calculate and print shared time 00:00:00.0156250 seconds