Java - puntuación oficial de 4.056s
La idea principal de esto es nunca asignar memoria cuando no es necesaria. La única excepción son las primitivas, que el compilador debe optimizar de todos modos. Todo lo demás se almacena como máscaras y conjuntos de operaciones realizadas en cada paso, que se pueden deshacer cuando se completa el paso de recursión.
Aproximadamente la mitad de todos los sudokus se resuelven por completo sin retroceder, pero si presiono ese número más alto, el tiempo general parece ser más lento. Estoy planeando reescribir esto en C ++ y optimizar aún más, pero este solucionador se está convirtiendo en un gigante.
Quería implementar el mayor almacenamiento en caché posible, lo que condujo a algunos problemas. Por ejemplo, si hay dos celdas en la misma fila que solo pueden tener el número 6, entonces hemos llegado a un caso imposible, y deberíamos volver al rastreo. Pero como calculé todas las opciones en un barrido y luego coloqué los números en las celdas con una sola posibilidad, no verifiqué que había colocado un número en la misma fila justo antes. Esto lleva a soluciones imposibles.
Con todo contenido en los arreglos definidos en la parte superior, el uso de memoria del solucionador real es de aproximadamente 216kB. La parte principal del uso de la memoria proviene de la matriz que contiene todos los rompecabezas y los controladores de E / S en Java.
EDITAR : Tengo una versión que está traducida a C ++ ahora, pero no es mucho más rápida. El tiempo oficial es de alrededor de 3,5 segundos, lo que no es una gran mejora. Creo que el problema principal con mi implementación es que mantengo mis máscaras como matrices en lugar de máscaras de bits. Intentaré analizar la solución de Arnauld para ver qué se puede hacer para mejorarla.
import java.util.HashMap;
import java.util.ArrayList;
import java.util.Arrays;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.File;
import java.io.PrintWriter;
public class Sudoku {
final private int[] unsolvedBoard;
final private int[] solvedBoard;
final private int[][] neighbors;
final private int[][] cells;
private static int[] clues;
final private int[][] mask;
final private int[] formattedMask;
final private int[][] placedMask;
final private boolean[][][] lineMask;
final private int[] lineCounters;
final private int[][] sectionCounters;
final private int[][] sectionMask;
private int easySolved;
private boolean isEasy;
private int totEasy;
private int placedNumbers;
public long totTime = 0;
private boolean solutionFound;
public long lastPrint;
private boolean shouldPrint;
private boolean isImpossible = false;
public Sudoku() {
mask = new int[81][9];
formattedMask = new int[81];
placedMask = new int[64][64];
lineMask = new boolean[64][81][9];
sectionCounters = new int[9][27];
sectionMask = new int[9][27];
lineCounters = new int[64];
neighbors = new int[81][20];
unsolvedBoard = new int[81];
solvedBoard = new int[81];
cells = new int[][] {{0 ,1 ,2 ,9 ,10,11,18,19,20},
{3 ,4 ,5 ,12,13,14,21,22,23},
{6 ,7 ,8 ,15,16,17,24,25,26},
{27,28,29,36,37,38,45,46,47},
{30,31,32,39,40,41,48,49,50},
{33,34,35,42,43,44,51,52,53},
{54,55,56,63,64,65,72,73,74},
{57,58,59,66,67,68,75,76,77},
{60,61,62,69,70,71,78,79,80}};
}
final public long solveSudoku(int[] board, int clue) {
long t1 = 0,t2 = 0;
t1 = System.nanoTime();
System.arraycopy(board, 0, unsolvedBoard, 0, 81);
System.arraycopy(board, 0, solvedBoard, 0, 81);
placedNumbers = 0;
solutionFound = false;
isEasy = true;
isImpossible = false;
for (int[] i : mask) {
Arrays.fill(i, 0);
}
for (boolean[][] i : lineMask) {
for (boolean[] j : i) {
Arrays.fill(j, false);
}
}
for (int i = 0; i < 81; i++) {
if (solvedBoard[i] != -1) {
put(i, solvedBoard[i]);
placedNumbers++;
}
}
solve(0, 0);
t2 = System.nanoTime();
easySolved += isEasy ? 1 : 0;
if (solutionFound && placedNumbers == 81) {
totTime += t2-t1;
if (shouldPrint || t2-t1 > 5*1_000_000_000L) {
System.out.print(String.format(
"Solution from %2d clues found in %7s",
clue,
printTime(t1, t2)
));
shouldPrint = false;
if (t2-t1 > 1*1000_000_000L) {
System.out.println();
display2(board, solvedBoard);
}
}
} else {
System.out.println("No solution");
display2(unsolvedBoard, solvedBoard);
return -1;
}
return t2 - t1;
}
final private void solve(int v, int vIndex) {
lineCounters[vIndex] = 0;
int easyIndex = placeEasy(vIndex);
if (isImpossible) {
resetEasy(vIndex, easyIndex);
resetLineMask(vIndex);
return;
}
if (placedNumbers == 81) {
solutionFound = true;
return;
}
// if (true) {
// return;
// }
// either get the next empty cell
// while (v < 81 && solvedBoard[v] >= 0) {
// v++;
// }
// or get the cell with the fewest options
generateFormattedMasks();
int minOptions = 9;
for (int i = 0; i < 81; i++) {
int options = formattedMask[i] & 0xffff;
if (options > 0 && options < minOptions) {
minOptions = options;
v = i;
}
if (options == 0 && solvedBoard[i] == -1) {
isImpossible = true;
}
}
if (!isImpossible) {
for (int c = 0; c < 9; c++) {
if (isPossible(v, c)) {
isEasy = false;
put(v, c);
placedNumbers++;
solve(v + 1, vIndex + 1);
if (solutionFound) {
return;
}
unput(v, c);
placedNumbers--;
}
}
}
resetEasy(vIndex, easyIndex);
resetLineMask(vIndex);
}
final private void resetEasy(int vIndex, int easyIndex) {
for (int i = 0; i < easyIndex; i++) {
int tempv2 = placedMask[vIndex][i];
int c2 = solvedBoard[tempv2];
unput(tempv2, c2);
placedNumbers--;
}
}
final private void resetLineMask(int vIndex) {
if (lineCounters[vIndex] > 0) {
for (int i = 0; i < 81; i++) {
for (int c = 0; c < 9; c++) {
if (lineMask[vIndex][i][c]) {
enable(i, c);
lineMask[vIndex][i][c] = false;
}
}
}
}
isImpossible = false;
}
final private int placeEasy(int vIndex) {
int easyIndex = 0;
int lastPlaced = 0, tempPlaced = 0, easyplaced = 0;
int iter = 0;
while (placedNumbers > lastPlaced+1) {
lastPlaced = placedNumbers;
tempPlaced = 0;
while (placedNumbers > tempPlaced + 5) {
tempPlaced = placedNumbers;
easyIndex = placeNakedSingles(vIndex, easyIndex);
if (isImpossible) {
return easyIndex;
}
}
tempPlaced = 0;
while (placedNumbers < 55*1 && placedNumbers > tempPlaced + 2) {
tempPlaced = placedNumbers;
easyIndex = placeHiddenSingles(vIndex, easyIndex);
if (isImpossible) {
return easyIndex;
}
}
tempPlaced = 0;
while (placedNumbers < 65*1 && placedNumbers > tempPlaced + 1) {
tempPlaced = placedNumbers;
easyIndex = placeNakedSingles(vIndex, easyIndex);
if (isImpossible) {
return easyIndex;
}
}
if (iter < 2 && placedNumbers < 55*1) {
checkNakedTriples(vIndex);
}
if (placedNumbers < 45*1) {
checkNakedDoubles(vIndex);
identifyLines(vIndex);
}
iter++;
}
return easyIndex;
}
final private int placeNakedSingles(int vIndex, int easyIndex) {
generateFormattedMasks();
for (int tempv = 0; tempv < 81; tempv++) {
int possibilities = formattedMask[tempv];
if ((possibilities & 0xffff) == 1) {
possibilities >>= 16;
int c = 0;
while ((possibilities & 1) == 0) {
possibilities >>= 1;
c++;
}
if (isPossible(tempv, c)) {
put(tempv, c);
placedMask[vIndex][easyIndex++] = tempv;
placedNumbers++;
} else {
isImpossible = true;
return easyIndex;
}
} else if (possibilities == 0 && solvedBoard[tempv] == -1) {
isImpossible = true;
return easyIndex;
}
}
return easyIndex;
}
final private int placeHiddenSingles(int vIndex, int easyIndex) {
for (int[] i : sectionCounters) {
Arrays.fill(i, 0);
}
for (int c = 0; c < 9; c++) {
for (int v = 0; v < 81; v++) {
if (isPossible(v, c)) {
int cell = 3 * (v / 27) + ((v / 3) % 3);
sectionCounters[c][v / 9]++;
sectionCounters[c][9 + (v % 9)]++;
sectionCounters[c][18 + cell]++;
sectionMask[c][v / 9] = v;
sectionMask[c][9 + (v % 9)] = v;
sectionMask[c][18 + cell] = v;
}
}
int v;
for (int i = 0; i < 9; i++) {
if (sectionCounters[c][i] == 1) {
v = sectionMask[c][i];
if (isPossible(v, c)) {
put(v, c);
placedMask[vIndex][easyIndex++] = v;
placedNumbers++;
int cell = 3 * (v / 27) + ((v / 3) % 3);
sectionCounters[c][9 + (v%9)] = 9;
sectionCounters[c][18 + cell] = 9;
} else {
isImpossible = true;
return easyIndex;
}
}
}
for (int i = 9; i < 18; i++) {
if (sectionCounters[c][i] == 1) {
v = sectionMask[c][i];
if (isPossible(v, c)) {
put(v, c);
placedMask[vIndex][easyIndex++] = v;
int cell = 3 * (v / 27) + ((v / 3) % 3);
placedNumbers++;
sectionCounters[c][18 + cell]++;
} else {
isImpossible = true;
return easyIndex;
}
}
}
for (int i = 18; i < 27; i++) {
if (sectionCounters[c][i] == 1) {
v = sectionMask[c][i];
if (isPossible(v, c)) {
put(v, c);
placedMask[vIndex][easyIndex++] = v;
placedNumbers++;
} else {
isImpossible = true;
return easyIndex;
}
}
}
}
return easyIndex;
}
final private int getFormattedMask(int v) {
if (solvedBoard[v] >= 0) {
return 0;
}
int x = 0;
int y = 0;
for (int c = 8; c >= 0; c--) {
x <<= 1;
x += mask[v][c] == 0 ? 1 : 0;
y += mask[v][c] == 0 ? 1 : 0;
}
x <<= 16;
return x + y;
}
final private int getCachedMask(int v) {
return formattedMask[v];
}
final private void generateFormattedMasks() {
for (int i = 0; i < 81; i++) {
formattedMask[i] = getFormattedMask(i);
}
}
final private void generateFormattedMasks(int[] idxs) {
for (int i : idxs) {
formattedMask[i] = getFormattedMask(i);
}
}
final private void checkNakedDoubles(int vIndex) {
generateFormattedMasks();
for (int i = 0; i < 81; i++) {
int bitmask = formattedMask[i];
if ((bitmask & 0xffff) == 2) {
for (int j = i+1; j < (i/9+1)*9; j++) {
int bitmask_j = formattedMask[j];
if (bitmask == bitmask_j) {
bitmask >>= 16;
int c0, c1, k = 0;
while ((bitmask & 1) == 0) {
k++;
bitmask >>= 1;
}
c0 = k;
bitmask >>= 1;
k++;
while ((bitmask & 1) == 0) {
k++;
bitmask >>= 1;
}
c1 = k;
for (int cell = (i/9)*9; cell < (i/9+1)*9; cell++) {
if (cell != i && cell != j) {
if (!lineMask[vIndex][cell][c0]) {
disable(cell, c0);
lineMask[vIndex][cell][c0] = true;
lineCounters[vIndex]++;
}
if (!lineMask[vIndex][cell][c1]) {
disable(cell, c1);
lineMask[vIndex][cell][c1] = true;
lineCounters[vIndex]++;
}
}
}
}
}
}
}
for (int idx = 0; idx < 81; idx++) {
int i = (idx%9)*9 + idx/9;
int bitmask = formattedMask[i];
if ((bitmask & 0xffff) == 2) {
for (int j = i+9; j < 81; j += 9) {
int bitmask_j = formattedMask[j];
if (bitmask == bitmask_j) {
bitmask >>= 16;
int c0, c1, k = 0;
while ((bitmask & 1) == 0) {
k++;
bitmask >>= 1;
}
c0 = k;
bitmask >>= 1;
k++;
while ((bitmask & 1) == 0) {
k++;
bitmask >>= 1;
}
c1 = k;
for (int cell = i % 9; cell < 81; cell += 9) {
if (cell != i && cell != j) {
if (!lineMask[vIndex][cell][c0]) {
disable(cell, c0);
lineMask[vIndex][cell][c0] = true;
lineCounters[vIndex]++;
}
if (!lineMask[vIndex][cell][c1]) {
disable(cell, c1);
lineMask[vIndex][cell][c1] = true;
lineCounters[vIndex]++;
}
}
}
}
}
}
}
for (int idx = 0; idx < 9; idx++) {
for (int i = 0; i < 9; i++) {
int bitmask = formattedMask[cells[idx][i]];
if ((bitmask & 0xffff) == 2) {
for (int j = i+1; j < 9; j++) {
int bitmask_j = formattedMask[cells[idx][j]];
if (bitmask == bitmask_j) {
bitmask >>= 16;
int c0, c1, k = 0;
while ((bitmask & 1) == 0) {
k++;
bitmask >>= 1;
}
c0 = k;
bitmask >>= 1;
k++;
while ((bitmask & 1) == 0) {
k++;
bitmask >>= 1;
}
c1 = k;
for (int cellIdx = 0; cellIdx < 9; cellIdx++) {
if (cellIdx != i && cellIdx != j) {
int cell = cells[idx][cellIdx];
if (!lineMask[vIndex][cell][c0]) {
disable(cell, c0);
lineMask[vIndex][cell][c0] = true;
lineCounters[vIndex]++;
}
if (!lineMask[vIndex][cell][c1]) {
disable(cell, c1);
lineMask[vIndex][cell][c1] = true;
lineCounters[vIndex]++;
}
}
}
}
}
}
}
}
}
final private void checkNakedTriples(int vIndex) {
generateFormattedMasks();
for (int i = 0; i < 81; i++) {
int bitmask = formattedMask[i];
if ((bitmask & 0xffff) == 3) {
for (int j = i+1; j < (i/9+1)*9; j++) {
int bitmask_j = formattedMask[j];
if (bitmask_j > 0 && bitmask == (bitmask | bitmask_j)) {
for (int k = j+1; k < (i/9+1)*9; k++) {
int bitmask_k = formattedMask[k];
if (bitmask_k > 0 && bitmask == (bitmask | bitmask_k)) {
int bitmask_shifted = bitmask >> 16;
int c0, c1, c2, l = 0;
while ((bitmask_shifted & 1) == 0) {
l++;
bitmask_shifted >>= 1;
}
c0 = l;
bitmask_shifted >>= 1;
l++;
while ((bitmask_shifted & 1) == 0) {
l++;
bitmask_shifted >>= 1;
}
c1 = l;
bitmask_shifted >>= 1;
l++;
while ((bitmask_shifted & 1) == 0) {
l++;
bitmask_shifted >>= 1;
}
c2 = l;
for (int cell = (i/9)*9; cell < (i/9+1)*9; cell++) {
if (cell != i && cell != j && cell != k) {
if (!lineMask[vIndex][cell][c0]) {
disable(cell, c0);
lineMask[vIndex][cell][c0] = true;
lineCounters[vIndex]++;
}
if (!lineMask[vIndex][cell][c1]) {
disable(cell, c1);
lineMask[vIndex][cell][c1] = true;
lineCounters[vIndex]++;
}
if (!lineMask[vIndex][cell][c2]) {
disable(cell, c2);
lineMask[vIndex][cell][c2] = true;
lineCounters[vIndex]++;
}
}
}
}
}
}
}
}
}
for (int idx = 0; idx < 81; idx++) {
int i = (idx%9)*9 + idx/9;
int bitmask = formattedMask[i];
if ((bitmask & 0xffff) == 3) {
for (int j = i+9; j < 81; j += 9) {
int bitmask_j = formattedMask[j];
if (bitmask_j > 0 && bitmask == (bitmask | bitmask_j)) {
for (int k = j+9; k < 81; k += 9) {
int bitmask_k = formattedMask[k];
if (bitmask_k > 0 && bitmask == (bitmask | bitmask_k)) {
int bitmask_shifted = bitmask >> 16;
int c0, c1, c2, l = 0;
while ((bitmask_shifted & 1) == 0) {
l++;
bitmask_shifted >>= 1;
}
c0 = l;
bitmask_shifted >>= 1;
l++;
while ((bitmask_shifted & 1) == 0) {
l++;
bitmask_shifted >>= 1;
}
c1 = l;
bitmask_shifted >>= 1;
l++;
while ((bitmask_shifted & 1) == 0) {
l++;
bitmask_shifted >>= 1;
}
c2 = l;
for (int cell = i%9; cell < 81; cell += 9) {
if (cell != i && cell != j && cell != k) {
if (!lineMask[vIndex][cell][c0]) {
disable(cell, c0);
lineMask[vIndex][cell][c0] = true;
lineCounters[vIndex]++;
}
if (!lineMask[vIndex][cell][c1]) {
disable(cell, c1);
lineMask[vIndex][cell][c1] = true;
lineCounters[vIndex]++;
}
if (!lineMask[vIndex][cell][c2]) {
disable(cell, c2);
lineMask[vIndex][cell][c2] = true;
lineCounters[vIndex]++;
}
}
}
}
}
}
}
}
}
for (int idx = 0; idx < 9; idx++) {
for (int i = 0; i < 9; i++) {
int bitmask = formattedMask[cells[idx][i]];
if ((bitmask & 0xffff) == 3) {
for (int j = i+1; j < 9; j++) {
int bitmask_j = formattedMask[cells[idx][j]];
if (bitmask_j > 0 && bitmask == (bitmask | bitmask_j)) {
for (int k = j+1; k < 9; k++) {
int bitmask_k = formattedMask[cells[idx][k]];
if (bitmask_k > 0 && bitmask == (bitmask | bitmask_k)) {
int bitmask_shifted = bitmask >> 16;
int c0, c1, c2, l = 0;
while ((bitmask_shifted & 1) == 0) {
l++;
bitmask_shifted >>= 1;
}
c0 = l;
bitmask_shifted >>= 1;
l++;
while ((bitmask_shifted & 1) == 0) {
l++;
bitmask_shifted >>= 1;
}
c1 = l;
bitmask_shifted >>= 1;
l++;
while ((bitmask_shifted & 1) == 0) {
l++;
bitmask_shifted >>= 1;
}
c2 = l;
for (int cellIdx = 0; cellIdx < 9; cellIdx++) {
if (cellIdx != i && cellIdx != j && cellIdx != k) {
int cell = cells[idx][cellIdx];
if (!lineMask[vIndex][cell][c0]) {
disable(cell, c0);
lineMask[vIndex][cell][c0] = true;
lineCounters[vIndex]++;
}
if (!lineMask[vIndex][cell][c1]) {
disable(cell, c1);
lineMask[vIndex][cell][c1] = true;
lineCounters[vIndex]++;
}
if (!lineMask[vIndex][cell][c2]) {
disable(cell, c2);
lineMask[vIndex][cell][c2] = true;
lineCounters[vIndex]++;
}
}
}
}
}
}
}
}
}
}
}
final private void identifyLines(int vIndex) {
int disabledLines = 0;
int[][] tempRowMask = new int[3][9];
int[][] tempColMask = new int[3][9];
for (int i = 0; i < 9; i++) {
for (int c = 0; c < 9; c++) {
for (int j = 0; j < 3; j++) {
tempRowMask[j][c] = 0;
tempColMask[j][c] = 0;
}
for (int j = 0; j < 9; j++) {
if (mask[cells[i][j]][c] == 0) {
tempRowMask[j/3][c]++;
tempColMask[j%3][c]++;
}
}
int rowCount = 0;
int colCount = 0;
int rowIdx = -1, colIdx = -1;
for (int j = 0; j < 3; j++) {
if (tempRowMask[j][c] > 0) {
rowCount++;
rowIdx = j;
}
if (tempColMask[j][c] > 0) {
colCount++;
colIdx = j;
}
}
if (rowCount == 1) {
for (int j = (i/3)*3; j < (i/3 + 1)*3; j++) {
if (j != i) {
for (int k = rowIdx*3; k < (rowIdx+1)*3; k++) {
int cell = cells[j][k];
if (!lineMask[vIndex][cell][c]) {
disable(cell, c);
lineMask[vIndex][cell][c] = true;
lineCounters[vIndex]++;
}
}
}
}
}
if (colCount == 1) {
for (int j = i % 3; j < 9; j += 3) {
if (j != i) {
for (int k = colIdx; k < 9; k += 3) {
int cell = cells[j][k];
if (!lineMask[vIndex][cell][c]) {
disable(cell, c);
lineMask[vIndex][cell][c] = true;
lineCounters[vIndex]++;
}
}
}
}
}
}
}
}
final private boolean isPossible(int v, int c) {
return mask[v][c] == 0;
}
final private int checkMask(int[][] neighbors, int v, int c) {
int tempValue = 0;
for (int n : neighbors[v]) {
if (mask[n][c] > 0) {
tempValue++;
}
}
return tempValue;
}
final private void put(int v, int c) {
solvedBoard[v] = c;
for (int i : neighbors[v]) {
mask[i][c]++;
}
for (int i = 0; i < 9; i++) {
mask[v][i]++;
}
}
final private void disable(int v, int c) {
mask[v][c]++;
}
final private void unput(int v, int c) {
solvedBoard[v] = -1;
for (int i : neighbors[v]) {
mask[i][c]--;
}
for (int i = 0; i < 9; i++) {
mask[v][i]--;
}
}
final private void enable(int v, int c) {
// enables++;
mask[v][c]--;
}
public String getString(int[] board) {
StringBuilder s = new StringBuilder();
for (int i : board) {
s.append(i+1);
}
return s.toString();
}
public long getTime() {
return totTime;
}
public static String printTime(long t1, long t2) {
String unit = " ns";
if (t2-t1 > 10000) {
unit = " us";
t1 /= 1000; t2 /= 1000;
}
if (t2-t1 > 10000) {
unit = " ms";
t1 /= 1000; t2 /= 1000;
}
if (t2-t1 > 10000) {
unit = " seconds";
t1 /= 1000; t2 /= 1000;
}
return (t2-t1) + unit;
}
public void display(int[] board) {
for (int i = 0; i < 9; i++) {
if (i % 3 == 0) {
System.out.println("+-----+-----+-----+");
}
for (int j = 0; j < 9; j++) {
if (j % 3 == 0) {
System.out.print("|");
} else {
System.out.print(" ");
}
if (board[i*9+j] != -1) {
System.out.print(board[i*9+j]+1);
} else {
System.out.print(" ");
}
}
System.out.println("|");
}
System.out.println("+-----+-----+-----+");
}
public void display2(int[] board, int[] solved) {
for (int i = 0; i < 9; i++) {
if (i % 3 == 0) {
System.out.println("+-----+-----+-----+ +-----+-----+-----+");
}
for (int j = 0; j < 9; j++) {
if (j % 3 == 0) {
System.out.print("|");
} else {
System.out.print(" ");
}
if (board[i*9+j] != -1) {
System.out.print(board[i*9+j]+1);
} else {
System.out.print(" ");
}
}
System.out.print("| ");
for (int j = 0; j < 9; j++) {
if (j % 3 == 0) {
System.out.print("|");
} else {
System.out.print(" ");
}
if (solved[i*9+j] != -1) {
System.out.print(solved[i*9+j]+1);
} else {
System.out.print(" ");
}
}
System.out.println("|");
}
System.out.println("+-----+-----+-----+ +-----+-----+-----+");
}
private boolean contains(int[] a, int v) {
for (int i : a) {
if (i == v) {
return true;
}
}
return false;
}
public void connect() {
for (int i = 0; i < 81; i++) {
for (int j = 0; j < 20; j++) {
neighbors[i][j] = -1;
}
}
int[] n_count = new int[81];
HashMap<Integer,ArrayList<Integer>> map
= new HashMap<Integer,ArrayList<Integer>>();
for (int[] c: cells) {
ArrayList<Integer> temp = new ArrayList<Integer>();
for (int v : c) {
temp.add(v);
}
for (int v : c) {
map.put(v,temp);
}
}
for (int i = 0; i < 81; i++) {
for (int j = (i/9)*9; j < (i/9)*9 + 9; j++) {
if (i != j) {
neighbors[i][n_count[i]++] = j;
}
}
for (int j = i%9; j < 81; j += 9) {
if (i != j) {
neighbors[i][n_count[i]++] = j;
}
}
for (int j : map.get(i)) {
if (i != j) {
if (!contains(neighbors[i], j)) {
neighbors[i][n_count[i]++] = j;
}
}
}
}
}
public static int[][] getInput(String filename) {
int[][] boards;
try (BufferedInputStream in = new BufferedInputStream(
new FileInputStream(filename))) {
BufferedReader r = new BufferedReader(
new InputStreamReader(in, StandardCharsets.UTF_8));
int n = Integer.valueOf(r.readLine());
boards = new int[n][81];
clues = new int[n];
for (int i = 0; i < n; i++) {
for (int j = 0; j < 81; j++) {
int x = r.read();
boards[i][j] = x - 49;
clues[i] += x > 48 ? 1 : 0;
}
r.read();
}
r.close();
} catch (IOException ex) {
throw new RuntimeException(ex);
}
return boards;
}
private int getTotEasy() {
return totEasy;
}
public String getSolution() {
StringBuilder s = new StringBuilder(256);
for (int i : unsolvedBoard) {
s.append(i+1);
}
s.append(",");
for (int i : solvedBoard) {
s.append(i+1);
}
return s.toString();
}
public static void main (String[] args) {
long t0 = System.nanoTime();
Sudoku gc = new Sudoku();
File f;
PrintWriter p;
try {
f = new File("sudoku_output.txt");
p = new PrintWriter(f);
} catch (Exception e) {
return;
}
if (args.length != 1) {
System.out.println("Usage: java Sudoku <input_file>");
return;
}
int[][] boards = gc.getInput(args[0]);
long tinp = System.nanoTime();
gc.connect();
long t1 = System.nanoTime();
p.println(boards.length);
long maxSolveTime = 0;
int maxSolveIndex = 0;
long[] solveTimes = new long[boards.length];
for (int i = 0; i < boards.length; i++) {
long tempTime = System.nanoTime();
if (tempTime - gc.lastPrint > 200_000_000
|| i == boards.length - 1) {
gc.shouldPrint = true;
gc.lastPrint = tempTime;
System.out.print(String.format(
"\r(%7d/%7d) ", i+1, boards.length));
}
long elapsed = gc.solveSudoku(boards[i], gc.clues[i]);
if (elapsed == -1) {
System.out.println("Impossible: " + i);
}
if (elapsed > maxSolveTime) {
maxSolveTime = elapsed;
maxSolveIndex = i;
}
solveTimes[i] = elapsed;
p.println(gc.getSolution());
// break;
}
p.close();
long t2 = System.nanoTime();
Arrays.sort(solveTimes);
System.out.println();
System.out.println("Median solve time: "
+ gc.printTime(0, solveTimes[boards.length/2]));
System.out.println("Longest solve time: "
+ gc.printTime(0, maxSolveTime) + " for board " + maxSolveIndex);
gc.display(boards[maxSolveIndex]);
System.out.println();
System.out.println("Total time (including prints): "
+ gc.printTime(t0,t2));
System.out.println("Sudoku solving time: "
+ gc.printTime(0,gc.getTime()));
System.out.println("Average time per board: "
+ gc.printTime(0,gc.getTime()/boards.length));
System.out.println("Number of one-choice digits per board: "
+ String.format("%.2f", gc.getTotEasy()/(double)boards.length));
System.out.println("Easily solvable boards: " + gc.easySolved);
System.out.println("\nInput time: " + gc.printTime(t0,tinp));
System.out.println("Connect time: " + gc.printTime(tinp,t1));
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
}
}
}