private static Coordinates GetNextCoordinates(Coordinates currentCoordinates, SpiralDirections currentDirection)
{
var newCoordinates = new Coordinates { x = currentCoordinates.x, y = currentCoordinates.y };
switch (currentDirection)
{
case SpiralDirections.right:
newCoordinates.x++;
break;
case SpiralDirections.down:
newCoordinates.y++;
break;
case SpiralDirections.left:
newCoordinates.x--;
break;
case SpiralDirections.up:
newCoordinates.y--;
break;
}
return newCoordinates;
}
public static List<List<int>> GetNumberSpriralGrid(int dimension)
{
// build an empty grid
var totalCells = 0;
List<List<int>> grid = new List<List<int>>();
for (int i = 0; i < dimension; i++)
{
List<int> row = new List<int>();
for (var j= 0; j < dimension; j++)
{
row.Add(0);
totalCells++;
}
grid.Add(row);
}
// get the mid point
var mid = (dimension / 2) + 1;
var currentCoordinates = new Coordinates { x = mid - 1, y = mid - 1 };
var currentDirection = SpiralDirections.up;
grid[currentCoordinates.x][currentCoordinates.y] = 1;
var currentValue = 2;
while (currentValue <= totalCells)
{
var desiredCoordinates = GetNextCoordinates(currentCoordinates, GetNextDirection(currentDirection));
var currentCourseCooredinates = GetNextCoordinates(currentCoordinates, currentDirection);
if (grid[desiredCoordinates.x][desiredCoordinates.y] == 0)
{
grid[desiredCoordinates.x][desiredCoordinates.y] = currentValue;
currentCoordinates = desiredCoordinates;
currentDirection = GetNextDirection(currentDirection);
}
else
{
grid[currentCourseCooredinates.x][currentCourseCooredinates.y] = currentValue;
currentCoordinates = currentCourseCooredinates;
}
currentValue++;
}
return grid;
}
