Renamed N to n

src/main/java/de/nqueensfaf/Solver.java

@@ -6,7 +6,7 @@
 
 public abstract class Solver {
 
-    protected int N;
+    protected int n;
 
     private volatile Status state = Status.IDLE;
     private Thread asyncSolverThread, bgThread;
@@ -98,7 +98,7 @@ public final <T extends Solver> T waitFor() {
     }
 
     private void preconditions() {
-	if (N == 0) {
+	if (n == 0) {
 	    state = Status.IDLE;
 	    throw new IllegalStateException("board size was not set");
 	}
@@ -116,7 +116,7 @@ private Thread backgroundThread(boolean updateConsumer, boolean autoSaver) {
 	return new Thread(() -> {
 	    // for autoSaver
 	    String filePath = config().autoSavePath;
-	    filePath = filePath.replaceAll("\\{N\\}", "" + N);
+	    filePath = filePath.replaceAll("\\{n\\}", "" + n);
 	    float progress = getProgress() * 100;
 	    float tmpProgress = progress;
 
@@ -167,13 +167,13 @@ else if (progress >= tmpProgress + config().autoSavePercentageStep) {
 
     protected int solveSmallBoard() {
 	solutionsSmallN = 0;
-	int mask = (1 << getN()) - 1;
+	int mask = (1 << n) - 1;
 	smallBoardNQ(0, 0, 0, 0, mask, mask);
 	return solutionsSmallN;
     }
 
     private void smallBoardNQ(int ld, int rd, int col, int row, int free, int mask) {
-	if (row == getN() - 1) {
+	if (row == n - 1) {
 	    solutionsSmallN++;
 	    return;
 	}
@@ -242,13 +242,13 @@ public final <T extends Solver> T setN(int n) {
 	if (n <= 0 || n > 31) {
 	    throw new IllegalArgumentException("board size must be a number between 0 and 32 (not inclusive)");
 	}
-	N = n;
+	this.n = n;
 	return (T) this;
     }
 
     // getters
     public final int getN() {
-	return N;
+	return n;
     }
 
     public final boolean isIdle() {

src/main/java/de/nqueensfaf/cli/CLI.java

@@ -56,8 +56,8 @@ public void setTaskFile(File taskFile) {
 	this.taskFile = taskFile;
     }
 
-    @Option(names = { "-N", "--board-size" }, paramLabel = "INT", required = false, description = "board size")
-    private int N = -69;
+    @Option(names = { "-n", "--board-size" }, paramLabel = "INT", required = false, description = "board size")
+    private int n = -69;
 
     @Option(names = { "-g", "--gpu" }, required = false, description = "execute on GPU('s)")
     private boolean executeOnGpu;
@@ -85,13 +85,13 @@ public void run() {
 
 	// validate settings
 	if (taskFile == null) {
-	    if (N == -69) {
+	    if (n == -69) {
 		System.err.println("Missing required option: '--board-size=INT'");
 		CommandLine.usage(this, System.err);
 		return;
 	    }
-	    if (N <= 0 || N >= 32) {
-		System.err.println("Invalid board size! Must be a number N with N > 0 and N < 32.");
+	    if (n <= 0 || n >= 32) {
+		System.err.println("Invalid board size! Must be a number  with  > 0 and  < 32.");
 		return;
 	    }
 	}
@@ -168,7 +168,7 @@ public void run() {
 	    if (taskFile != null) {
 		solver.load(taskFile);
 	    } else {
-		solver.setN(N);
+		solver.setN(n);
 		solver.solve();
 	    }
 

src/main/java/de/nqueensfaf/impl/CPUSolver.java

@@ -24,9 +24,9 @@
 
 public class CPUSolver extends Solver {
 
-    // for very small N it is overkill to use this method
+    // for very small n it is overkill to use this method
     // thus we use a straightforward recursive implementation of Jeff Somers Bit
-    // method for such N
+    // method for such n
     // smallestN marks the border, when to use this simpler solver
     private static final int smallestN = 6;
 
@@ -55,14 +55,14 @@ public CPUSolver() {
     @Override
     protected void run() {
 	start = System.currentTimeMillis();
-	if (N <= smallestN) { // if N is very small, use the simple Solver from the parent class
+	if (n <= smallestN) { // if n is very small, use the simple Solver from the parent class
 	    solutions = solveSmallBoard();
 	    end = System.currentTimeMillis();
 	    progress = 1;
 	    return;
 	}
 
-	utils.setN(N);
+	utils.setN(n);
 	if (!loaded) {
 	    genConstellations();
 	}
@@ -83,7 +83,7 @@ protected void run() {
 	// start the threads and wait until they are all finished
 	ExecutorService executor = Executors.newFixedThreadPool(config.threadcount);
 	for (i = 0; i < config.threadcount; i++) {
-	    CPUSolverThread cpuSolverThread = new CPUSolverThread(utils, N, threadConstellations.get(i));
+	    CPUSolverThread cpuSolverThread = new CPUSolverThread(utils, n, threadConstellations.get(i));
 	    threads.add(cpuSolverThread);
 	    executor.submit(cpuSolverThread);
 	}
@@ -126,7 +126,7 @@ protected void save_(String filepath) throws IOException {
 	Kryo kryo = Constants.kryo;
 	try (Output output = new Output(new GZIPOutputStream(new FileOutputStream(filepath)))) {
 	    kryo.writeObject(output,
-		    new SolverState(N, System.currentTimeMillis() - start + storedDuration, constellations));
+		    new SolverState(n, System.currentTimeMillis() - start + storedDuration, constellations));
 	    output.flush();
 	}
     }
@@ -181,18 +181,18 @@ public long getSolutions() {
     }
 
     private void genConstellations() {
-	// halfN half of N rounded up
-	final int halfN = (N + 1) / 2;
-	L = 1 << (N - 1);
-	mask = (1 << N) - 1;
+	// halfN half of n rounded up
+	final int halfN = (n + 1) / 2;
+	L = 1 << (n - 1);
+	mask = (1 << n) - 1;
 
 	// calculate starting constellations for no Queens in corners
 	for (int k = 1; k < halfN; k++) { // go through first col
-	    for (int l = k + 1; l < N - 1; l++) { // go through last col
-		for (int i = k + 1; i < N - 1; i++) { // go through first row
-		    if (i == N - 1 - l) // skip if occupied
+	    for (int l = k + 1; l < n - 1; l++) { // go through last col
+		for (int i = k + 1; i < n - 1; i++) { // go through first row
+		    if (i == n - 1 - l) // skip if occupied
 			continue;
-		    for (int j = N - k - 2; j > 0; j--) { // go through last row
+		    for (int j = n - k - 2; j > 0; j--) { // go through last row
 			if (j == i || l == j)
 			    continue;
 
@@ -207,8 +207,8 @@ private void genConstellations() {
 	}
 	// calculating start constellations with the first Queen on the corner square
 	// (0,0)
-	for (int j = 1; j < N - 2; j++) { // j is idx of Queen in last row
-	    for (int l = j + 1; l < N - 1; l++) { // l is idx of Queen in last col
+	for (int j = 1; j < n - 2; j++) { // j is idx of Queen in last row
+	    for (int l = j + 1; l < n - 1; l++) { // l is idx of Queen in last col
 		ijklList.add(utils.toijkl(0, j, 0, l));
 	    }
 	}
@@ -231,7 +231,7 @@ private void genConstellations() {
 	    // ld, rd, col, start_queens_ijkl for each constellation
 	    // occupy the board corresponding to the queens on the borders of the board
 	    // we are starting in the first row that can be free, namely row 1
-	    ld = (L >>> (i - 1)) | (1 << (N - k));
+	    ld = (L >>> (i - 1)) | (1 << (n - k));
 	    rd = (L >>> (i + 1)) | (1 << (l - 1));
 	    col = 1 | L | (L >>> i) | (L >>> j);
 	    // occupy diagonals of the queens j k l in the last row
@@ -242,7 +242,7 @@ private void genConstellations() {
 	    // counts all subconstellations
 	    counter = 0;
 	    // generate all subconstellations
-	    setPreQueens(ld, rd, col, k, l, 1, j == N - 1 ? 3 : 4);
+	    setPreQueens(ld, rd, col, k, l, 1, j == n - 1 ? 3 : 4);
 	    currentSize = constellations.size();
 	    // jkl and sym and start are the same for all subconstellations
 	    for (int a = 0; a < counter; a++) {
@@ -269,7 +269,7 @@ private void setPreQueens(int ld, int rd, int col, int k, int l, int row, int qu
 	// if not done or row k or l, just place queens and occupy the board and go
 	// further
 	else {
-	    int free = (~(ld | rd | col | (LD >>> (N - 1 - row)) | (RD << (N - 1 - row)))) & mask;
+	    int free = (~(ld | rd | col | (LD >>> (n - 1 - row)) | (RD << (n - 1 - row)))) & mask;
 	    int bit;
 
 	    while (free > 0) {