Changes

__global__ void superSolve(int * d_a) {

//Used to remember which row | col | box ( section ) have which values

__shared__ bool rowHas[N][N];

__shared__ bool colHas[N][N];

__shared__ bool boxHas[N][N];

//Used to ensure that the table has changed

__shared__ int added, past;

//Number of spaces which can place the number

__shared__ int rowCount[N][N];

__shared__ int colCount[N][N];

__shared__ int boxCount[N][N];

//Where the square is located in the Sudoku

int row = threadIdx.x;

int col = threadIdx.y;

int box = row / BOXWIDTH + (col / BOXWIDTH) * BOXWIDTH;

//Unique identifier for each square in row, col, box

//Corresponds to the generic Sudoku Solve

//Using a Sudoku to solve a Sudoku !!!

int offset = col + (row % BOXWIDTH) * BOXWIDTH + (box % BOXWIDTH);

//Squares location in the Sudoku

int gridIdx = col * N + row;

int at = d_a[gridIdx];

if (!gridIdx) { //Thread at 0,0 sets values

added = -1;

past = -2;

}

rowHas[col][row] = false;

colHas[col][row] = false;

boxHas[col][row] = false;

__syncthreads();

if (at != UNASSIGNED) {

rowHas[row][at - 1] = true;

boxHas[box][at - 1] = true;

}

//Previous loop has not changed any values

while (added != past) {

boxCount[col][row] = 0;

__syncthreads();

if (!gridIdx) //forget old change index

past = added;

int count = 0; //number of values which can fit in this square

int guess = at; //last value found which can fit in this square

for (int idx = 0; idx < N; ++idx) {

//Ensures that every square in each section is working on a different number in the section

__syncthreads();

}

//Only ONE value can fit in this spot

if (count == 1) {

}

__syncthreads();

if (at == UNASSIGNED) {

//Find values which can go in only one spot in the section