/* method which checks if the sudoku can be solved */
enum tag solver(struct sudoku sudoku_struct){
enum tag result = check_sudoku(&sudoku_struct);
if (result == INVALID){
return INVALID;
}
else if (result == COMPLETE){
solved_sudoku = sudoku_struct;
return COMPLETE;
}
else{
int i;
int j;
int counter = 0;
for(i = 0; i < 9; i++){
for(j = 0; j < 9; j++){
/* break out of the current iteration if a gap in the sudoku is found */
if(sudoku_struct.row_struct_array[i].items[j] == '.'){
goto exitloops;
}
}
}
exitloops:
for(int k = 1; k <10; k++){
if(multiplesolutions == 1){
return INVALID;
}
sudoku_struct.row_struct_array[i].items[j] = '0'+k;
if(solver(sudoku_struct) == COMPLETE){
counter++;
if(counter > 1){
multiplesolutions = 1;
return INVALID;
}
}
}
return COMPLETE;
}
return INVALID;
}
int assume1()
{
int k=0,allright;
while(k<5)
{
check4row();
check4col();
check4box();
thirdlogic();
k++;
}
allright=check_sudoku();
if(allright==0)
{
print();
getch();
exit(1);
}
else
{
rollback();
return(1);
}
}
