void Solver::findPossibleSlots(
const int box,
std::vector<std::stack<std::pair<int,int>>>& backTrackStack,
const int num) {
int highestRow = (box/3)*3; //Row of upper-left box
int highestCol = (box%3)*3; //Column of upper-left box
std::vector<std::pair<int,int>> shuffleVec;
/* Reversed the order so first item on stack is the upper-leftmost slot */
for(int rowIter = 2; rowIter >= 0; --rowIter) {
for(int colIter = 2; colIter >= 0; --colIter) {
bool existsRow = checkRow(highestRow + rowIter, num);
bool existsCol = checkColumn(highestCol + colIter, num);
if(!existsRow && !existsCol) {
shuffleVec.push_back(std::make_pair(rowIter,colIter));
#ifdef DEBUG
std::cout << "Adding possible slot " << rowIter << "," <<
colIter << " for " << num << std::endl;
#endif
}
else if(existsRow) break;
else continue;
}
}
std::random_device seedGen;
std::mt19937 randGen(seedGen());
std::shuffle(shuffleVec.begin(), shuffleVec.end(), randGen);
for(auto p : shuffleVec) backTrackStack[num-1].push(p);
}
void Solver::solveSemiSeed(const int semiSeed) {
/* Create RNG */
std::random_device seedGen;
std::mt19937 randGen(seedGen());
/* Generate semiSeed first */
int highestRow = (semiSeed/3)*3; //Row of upper-left box
int highestCol = (semiSeed%3)*3; //Column of upper-left box
std::array<int, 9> nums = {1,2,3,4,5,6,7,8,9};
std::shuffle(nums.begin(), nums.end(), randGen);
#ifdef DEBUG
std::cout << "nums:" << std::endl;
for(auto e : nums) std::cout << e << " ";
std::cout << std::endl;
#endif
for(int valIter = 0; valIter < 9; valIter++) {
for(int boxIter = 0; boxIter < 9; boxIter++) {
int currentRow = highestRow+boxIter/3;
int currentCol = highestCol+boxIter%3;
bool rowExists = checkRow(currentRow,nums[valIter]);
bool colExists = checkColumn(currentCol,nums[valIter]);
if(!rowExists && !colExists) {
if(
!sudokuBoard[semiSeed].addNumber(
boxIter/3,
boxIter%3,
nums[valIter])
) {
#ifdef DEBUG
std::cout << "Did not add " << nums[valIter] << " to semiSeed at "
<< boxIter/3 << "," << boxIter%3 << std::endl;
#endif
}
else break;
}
else if(rowExists) boxIter+=2;
else continue;
}
}
#ifdef DEBUG
std::cout << "semiSeed values:" << std::endl;
sudokuBoard[semiSeed].debugPrint();
#endif
}
int main(int argc, char* argv[])
{
size_t NumRows = pow(2, MyRow::NumCol);
if (argc > 1) {
NumRows = atoi(argv[1]);
}
std::mt19937 seedGen(getpid());
std::uniform_int_distribution<uint32_t> numGen(0, MaxRangeForEachCol);
typedef std::vector<MyRow> Table;
Table table;
// Enumerate all the combinations of possible columns
for (uint32_t idx = 0; idx < NumRows; idx ++)
{
std::vector<uint32_t> arr;
//std::generate_n(std::back_inserter(arr), MyRow::NumCol, [&] () -> uint32_t {return numGen(seedGen);});
//
//std::cout << "idx=" << idx << "{";
for (uint32_t col = 0; col < MyRow::NumCol; col ++)
{
// if the bit-rep of i-th row has j-th bit set
// set the j-th col for i-th row
auto bit = (((0x1 << col) & idx) >> col);
//std::cout << bit << ",";
arr.push_back(bit);
}
//std::cout << "}" << std::endl;
MyRow a(arr);
table.push_back(a);
}
// Sort table based on Morton code
std::sort(table.begin(), table.end());
// Print the rows sorted by Morton code
for (auto& row : table) {
std::cout << row << std::endl;
}
}
bool Solver::solve(const int box) {
/* Create RNG */
std::random_device seedGen;
std::mt19937 randGen(seedGen());
std::array<int, 9> nums = {1,2,3,4,5,6,7,8,9};
std::shuffle(nums.begin(), nums.end(), randGen);
bool isSolved = true;
#ifdef DEBUG
std::cout << "solve2() random array" << std::endl;
for(auto e : nums) std::cout << e << " ";
std::cout << std::endl;
#endif
/* Create backtrack stack */
std::vector<std::stack<std::pair<int,int>>> backTrackStack(9);
/* Find possible slots for each value */
for(int number = 1; number <= 9; ++number) findPossibleSlots(box, backTrackStack, number);
for(int numsIter = 0; numsIter < 9; ++numsIter) {
int number = nums[numsIter]-1;
if(backTrackStack[number].empty()) {
#ifdef DEBUG
std::cout << "Empty at " << number+1 << std::endl;
#endif
findPossibleSlots(box, backTrackStack, number+1);
numsIter--;
if(numsIter == -1) {
#ifdef DEBUG
std::cout << "No solution possible for box " << box << std::endl;
#endif
isSolved = false;
break;
}
number = nums[numsIter]-1; //Since numsIter is already decremented
auto slot = backTrackStack[number].top();
int row = std::get<0>(slot);
int col = std::get<1>(slot);
sudokuBoard[box].removeNumber(row,col,number+1);
backTrackStack[number].pop();
numsIter--; //Decrement even further
continue;
}
auto slot = backTrackStack[number].top();
int row = std::get<0>(slot);
int col = std::get<1>(slot);
#ifdef DEBUG1
std::cout << "Adding " << number+1 << " at " << row << "," << col << std::endl;
#endif
if(!sudokuBoard[box].addNumber(row, col, number+1)) {
#ifdef DEBUG1
std::cout << "Rejected " << number+1 << " at " << row << "," << col << std::endl;
#endif
/* Remove invalid slots */
backTrackStack[number].pop();
numsIter--;
if(backTrackStack[number].empty()) {
#ifdef DEBUG
std::cout << "Empty at " << number+1 << std::endl;
#endif
findPossibleSlots(box, backTrackStack, number+1);
number = nums[numsIter]-1; //Since numsIter is already decremented
slot = backTrackStack[number].top();
row = std::get<0>(slot);
col = std::get<1>(slot);
sudokuBoard[box].removeNumber(row,col,number+1);
backTrackStack[number].pop();
numsIter--; //Decrement even further
if(numsIter <= -1) {
#ifdef DEBUG
std::cout << "No solution possible for box " << box << std::endl;
#endif
isSolved = false;
break;
}
}
}
#ifdef DEBUG1
else std::cout << "Added!" << std::endl;
#endif
} //End of for-loop
return isSolved;
}