当然当你击中sudo[row][col] = 0 ;代码你刚刚尝试完一个正方形中的每个值，但没有发现其中任何一个的解决方案。当然，这就是你决定放弃并处于无解状态的时刻。
进一步思考——我怀疑我只是接近正确。如果你点击这个代码and这是first您正在尝试的单元格（即您找到的第一个空单元格）那么这就是您的失败时刻。
顺便说一句 - 我不确定使用异常来指示您在评论中建议的解决方案是个好主意。
现在，这正确地拒绝了您发布的板 - 请注意，不仅第一行有两个“3”，第一列也有两个“5”。这段代码现在似乎对我有用。也许你可以在一种不溶性的物质上尝试一下。
public class Test {
static final int S = 9;
int[][] sudo;
public Test() {
// Just leave it empty.
sudo = new int[S][S];
}
public Test(int[][] sudo) {
this.sudo = sudo;
}
// This number should not appear anywhere in the row.
public boolean checkHorizontal(int row, int num) {
for (int i = 0; i < S; i++) {
if (sudo[row][i] == num) {
return false;
}
}
return true;
}
// This number should not appear anywhere in the col.
public boolean checkVertical(int col, int num) {
for (int i = 0; i < S; i++) {
if (sudo[i][col] == num) {
return false;
}
}
return true;
}
// This number should not appear anywhere in the box.
private boolean checkBox(int row, int col, int num) {
// Round down to nearest 3.
int r = (row / 3) * 3;
int c = (col / 3) * 3;
for (int i = r; i < r + 3; i++) {
for (int j = c; j < c + 3; j++) {
if (sudo[i][j] == num) {
return false;
}
}
}
return true;
}
boolean check(int row, int col, int num) {
// All checks must pass.
return checkHorizontal(row, num)
&& checkVertical(col, num)
&& checkBox(row, col, num);
}
public boolean solve(int row, int col) {
// Got to the end?
if (row >= S) {
//Gelöst
return true;
}
// If the cell is empty
if (sudo[row][col] == 0) {
// Find a valid number for the empty cell
for (int num = 1; num < 10; num++) {
// Can this number be put there?
if (check(row, col, num)) {
// Yes!
sudo[row][col] = num;
// Try that.
if (next(row, col)) {
return true;
}
}
}
// Clean up.
sudo[row][col] = 0;
} else {
// Move on.
if (next(row, col)) {
return true;
}
}
// Failed to find a solution.
return false;
}
//Ruft solve für das nächste Feld auf
public boolean next(int row, int col) {
if (col < S - 1) {
// Step right.
return solve(row, col + 1);
} else {
// Step down.
return solve(row + 1, 0);
}
}
public boolean boardOk() {
// Initial test to ensure it is a valid array.
// Must have that many rows.
boolean ok = sudo.length == S;
for (int row = 0; ok && row < S; row++) {
// Each row must be that long.
ok &= sudo[row].length == S;
for (int col = 0; ok && col < S; col++) {
// Each filled square must be valid.
if (sudo[row][col] != 0) {
int num = sudo[row][col];
// Remove it.
sudo[row][col] = 0;
// Check it can be added.
ok &= check(row, col, num);
// Put it back.
sudo[row][col] = num;
}
}
}
return ok;
}
void solve() {
if (boardOk()) {
boolean solved = solve(0, 0);
if (solved) {
System.out.println("Solved!");
print();
}
} else {
System.out.println("Insoluble!");
print();
}
}
public void print() {
for (int i = 0; i < sudo.length; i++) {
System.out.println(Arrays.toString(sudo[i]));
}
}
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
new Test().solve();
int[][] test = {
{0, 0, 6, 5, 8, 3, 3, 2, 7},
{0, 0, 0, 0, 9, 0, 0, 5, 0},
{5, 8, 0, 0, 0, 0, 0, 0, 3},
{0, 3, 1, 0, 4, 0, 5, 0, 0},
{0, 0, 0, 9, 2, 0, 3, 0, 6},
{0, 0, 0, 0, 0, 0, 0, 0, 1},
{3, 4, 2, 0, 0, 6, 9, 1, 5},
{5, 0, 5, 4, 0, 9, 0, 3, 2},
{0, 1, 0, 0, 0, 0, 0, 0, 4},};
new Test(test).solve();
}
}
