static void Main(string[] args)
{
int[,] matrix = MatrixHelper.ReadMap();
int size = matrix.GetLength(0);
int[] startPosition = Surveyor.GetStartEndPositions(matrix, startEndValue: 2);
int[] endPosition = Surveyor.GetStartEndPositions(matrix, startEndValue: 1);
List <int[]> shortestPath;
int[,] listToArray; // couldn't find another way to convert only once but use in 2 places, needed for easier List<int[]> to int[,] comparison.
PrintHeader(width: size);
PrintContent(matrix, pathList: listToArray = null); // Basic map representation; with color coded walls, start & end positions.
PrintFooter(width: size);
Console.Write($"\nThe designated starting position coordinates (x, y) are: [ {startPosition[1]} , {startPosition[0]} ].\n" +
$"The designated ending position coordinates (x, y) are: [ {endPosition[1]} , {endPosition[0]} ].\n" +
"--------------------\n");
int[,] weightedMatrix = Surveyor.Surveying(matrix);
Console.WriteLine("Survey complete. Looking for optimal path..\n" +
"--------------------\n" +
$"Survey data integrity (OK if > 1): {weightedMatrix.Length} .");
shortestPath = PathFinder.PathCounter(weightedMatrix, startPosition, endPosition);
PrintResult(weightedMatrix, startPosition, endPosition, pathList: shortestPath);
Console.WriteLine("\n--------------------\n");
listToArray = ListToArray(shortestPath);
PrintContent(matrix, pathList: listToArray); // Basic map representation; with color coded walls, start & end positions, plus the shortest path.
Console.WriteLine("\n--------------------\nEnd.\n");
}
/// <summary>
/// Look around the current cell clockwise, using the 4 primary directions: up (x, y+1), right (x+1, y), down (x, y-1) and left (x-1, y).
/// </summary>
/// <param name="mapData">The matrix previously extracted from the input file.</param>
/// <returns>The surveyed copy of the map where instead of 0-s the passable cell values are the cell-step distance from the starting cell.</returns>
public static int[,] Surveying(int[,] mapData)
{
int[,] surveyData = new int[mapData.GetLength(0), mapData.GetLength(0)];
addDefaultSurveyData(surveyData);
int[] startPos = GetStartEndPositions(mapData, startEndValue: 2); // The "startEndValue" value is found inside the "MapData" file.
int[] endPos = GetStartEndPositions(mapData, startEndValue: 1);
// Buffer, put here the just checked clear cells (did not already have a cost, no walls) to peek around next cycle.
Queue <int[]> waiting = new Queue <int[]>();
// ----- The below arrays are Declared & Initialized here because they are parameters for more than one following code brackets. ----- //
// --------------------------------- //
// Start cell row & column indexes.
int srowi = startPos[0];
int scoli = startPos[1];
// Set current position to the coordinates where the Survey will start -- from the End Goal ("endPos").
int[] curPos = endPos;
int rowi = curPos[0];
int coli = curPos[1];
// Store coordinates of the cell we are looking at at any given time, around the current cell we are at.
int[] lookingAt = new int[2];
int xi = lookingAt[0];
int yi = lookingAt[1];
// --------------------------------- //
bool lookAtIsStart, lessThanIntMaxSize, isInsideBounds, isPassableCell;
surveyData[rowi, coli] = 0; // Surveyor start coordinate's cell cost ; also the first discovered cell.
waiting.Enqueue(curPos);
while (waiting.Count != 0)
{
Array.Copy(waiting.Dequeue(), curPos, 2); // Take the next one from the queue as the current position to look around.
rowi = curPos[0];
coli = curPos[1];
for (int cy = 1; cy <= 4; cy++) // Looking cycle: up, right, down, left.
{
lookingAt = MatrixHelper.SwitchView(rowi, coli, cy);
xi = lookingAt[0];
yi = lookingAt[1];
isInsideBounds = isInside(mapData, xi, yi);
if (isInsideBounds == false)
{
isPassableCell = false;
}
else
{
isPassableCell = isPassable(mapData, surveyData, xi, yi);
}
if (isInsideBounds == true && isPassableCell == true)
{
// Booleans.
lessThanIntMaxSize = (surveyData[rowi, coli] + 1 <= int.MaxValue);
lookAtIsStart = (xi == srowi && yi == scoli);
if (lookAtIsStart)
{
// Check against too large matrix size.
// Since each cell is given an "integer" type weight, if the area is too big the value could reach past the type's maximum value.
if (lessThanIntMaxSize)
{
surveyData[xi, yi] = surveyData[rowi, coli] + 1;
return(surveyData);
}
else
{
throw new OverflowException("ERROR.. There are too many cells to map with BFS.");
}
}
if (lessThanIntMaxSize)
{
surveyData[xi, yi] = surveyData[rowi, coli] + 1;
int[] t = new int[2];
Array.Copy(lookingAt, t, lookingAt.Length);
waiting.Enqueue(t); // Place what was just marked in the queue to be looked around later.
}
else
{
throw new OverflowException("ERROR.. There are too many cells to map with BFS.");
}
}
}
}
lookAtIsStart = (xi == srowi && yi == scoli);
if (lookAtIsStart)
{
Console.WriteLine($"FINALLY.. Print out weighted matrix; {yi}, {xi} .");
return(surveyData);
}
else
{
Console.WriteLine("ERROR.. Target coordinates cannot be reached!\n" +
"Check \"MapData.txt\" making sure there is NO obstruction between the desired Start and End positions.");
return(new int[0, 0]);
}
}