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#include <array>
#include <vector>
#include <set>
#include <iostream>
#include <utility>
// https://raw.githubusercontent.com/agauniyal/rang/master/include/rang.hpp
#include "rang.hpp"
// g++ --std=c++17 c2.cpp -O2 && ./a.out
namespace std
{
std::string to_string(bool in)
{
return in ? "true" : "false";
}
} // namespace std
class Board
{
public:
Board(const std::array<std::array<int, 9>, 9>& in)
:mBoard(in) { }
void fill(int* in)
{
for(size_t row = 0; row < mBoard.size(); row++)
{
for(size_t col = 0; col < mBoard.size(); col++)
{
*(in + (mBoard.size() * row) + col) = mBoard[row][col];
}
}
}
void checkPrint(const std::array<std::array<int, 9>, 9>& ref)
{
for(size_t row=0; row < mBoard.size(); row++)
{
for(size_t col=0; col < mBoard.size(); col++)
{
if(mBoard[row][col] == ref[row][col])
{
std::cout << mBoard[row][col] << " ";
}
else
{
std::cout << rang::fg::red << mBoard[row][col] << rang::fg::reset << " ";
}
}
std::cout << std::endl;
}
}
void print()
{
for(size_t row=0; row < mBoard.size(); row++)
{
for(size_t col=0; col < mBoard.size(); col++)
{
if(mBoard[row][col] != 0)
{
std::cout << mBoard[row][col] << " ";
}
else
{
std::cout << rang::fg::red << mBoard[row][col] << rang::fg::reset << " ";
}
}
std::cout << std::endl;
}
}
bool solve()
{
bool result = solveNext(0, 0);
std::cout << "Solved? " << std::to_string(result) << std::endl;
return result;
}
protected:
bool validRow(int num, size_t row)
{
return std::find(mBoard[row].begin(), mBoard[row].end(), num) == mBoard[row].end();
}
bool validCol(int num, size_t col)
{
// entire col
for(size_t irow = 0; irow < mBoard.size(); irow++)
{
if(mBoard[irow][col] == num)
{
return false;
}
}
return true;
}
bool validBox(int num, size_t row, size_t col)
{
size_t oRow = 3 * (row / 3);
size_t oCol = 3 * (col / 3);
// entire box
for(size_t irow = oRow; irow < oRow+3; irow++)
{
if(std::find(mBoard[irow].begin() + oCol, mBoard[irow].begin() + oCol + 3, num)
!= (mBoard[irow].begin() + oCol + 3))
{
return false;
}
}
return true;
}
bool isValid(int num, size_t row, size_t col)
{
return validRow(num, row) && validCol(num, col) && validBox(num, row, col);
}
bool solveNext(size_t row, size_t col)
{
if(mBoard[row][col] == 0)
{
for(int num = 1; num <=9; num++)
{
if(isValid(num, row, col))
{
mBoard[row][col] = num;
size_t nextCol = col == 8 ? 0 : col+1;
size_t nextRow = col == 8 ? row + 1 : row;
if(nextRow == 9 || solveNext(nextRow, nextCol))
{
return true;
}
mBoard[row][col] = 0;
}
}
}
else
{
size_t nextCol = col == 8 ? 0 : col + 1;
size_t nextRow = col == 8 ? row + 1 : row;
if(nextRow == 9 || solveNext(nextRow, nextCol))
{
return true;
}
}
return false;
}
std::array<std::array<int, 9>, 9> mBoard;
};
#ifdef BUILD_SHARED
extern "C" {
bool solve(int *data)
{
std::array< std::array<int, 9>, 9> input;
for(size_t row = 0; row < input.size(); row++)
{
for(size_t col = 0; col < input.size(); col++)
{
input[row][col] = *(data + (row * input.size()) + col);
}
}
Board board(input);
board.print();
bool ret = board.solve();
board.print();
board.fill(data);
return ret;
}
}
#else
int main()
{
std::array< std::array<int, 9>, 9> solved {{
{ 4, 3, 5, 2, 6, 9, 7, 8, 1 },
{ 6, 8, 2, 5, 7, 1, 4, 9, 3 },
{ 1, 9, 7, 8, 3, 4, 5, 6, 2 },
{ 8, 2, 6, 1, 9, 5, 3, 4, 7 },
{ 3, 7, 4, 6, 8, 2, 9, 1, 5 },
{ 9, 5, 1, 7, 4, 3, 6, 2, 8 },
{ 5, 1, 9, 3, 2, 6, 8, 7, 4 },
{ 2, 4, 8, 9, 5, 7, 1, 3, 6 },
{ 7, 6, 3, 4, 1, 8, 2, 5, 9 },
}};
std::array< std::array<int, 9>, 9> input {{
{ 0, 0, 0, 2, 6, 0, 7, 0, 1 },
{ 6, 8, 0, 0, 7, 0, 0, 9, 0 },
{ 1, 9, 0, 0, 0, 4, 5, 0, 0 },
{ 8, 2, 0, 1, 0, 0, 0, 4, 0 },
{ 0, 0, 4, 6, 0, 2, 9, 0, 0 },
{ 0, 5, 0, 0, 0, 3, 0, 2, 8 },
{ 0, 0, 9, 3, 0, 0, 0, 7, 4 },
{ 0, 4, 0, 0, 5, 0, 0,
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