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Sudoku Solver.c
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Sudoku Solver.c
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#include<stdio.h>
#include<conio.h>
#define MIN_VALUE '1'
#define MAX_VALUE '9'
#define EMPTY_VALUE '.'
#define NUM_VALUES (MAX_VALUE - MIN_VALUE + 1)
#define GRID_SIZE (NUM_VALUES * NUM_VALUES)
#define MAX_CELL (GRID_SIZE - 1)
#define TRUE 1
#define FALSE 0
typedef char value;
typedef int cell;
typedef value sudokuGrid[GRID_SIZE];
int hasSolution(sudokuGrid game);
void readGame(int game);
void showGame(int game);
int isFull(sudokuGrid game);
int getEmptyCell(sudokuGrid game);
int isLegal(sudokuGrid game, int candidateCell, int trialValue);
void setCell(sudokuGrid game, int candidateCell, int trialValue);
void clearCell(sudokuGrid game, int candidateCell);
int topLeftColumn(sudokuGrid game, int candidateCell);
int checkBox(int randCell, sudokuGrid game, int candidateCell, int trialValue);
int main(int argc, const char * argv[]){
sudokuGrid sample;
readGame(sample);
showGame(sample);
printf("\n\n\n\n");
if(hasSolution(sample)){
showGame(sample);
}
getch();
return 0;
}
int hasSolution(sudokuGrid game){
int solved;
cell candidateCell;
value trialValue;
if(isFull(game)){
solved = TRUE;
}else{
candidateCell = getEmptyCell(game);
trialValue = MIN_VALUE;
solved = FALSE;
while(!solved && (trialValue <= MAX_VALUE)){
if(isLegal(game, candidateCell, trialValue)){
setCell(game, candidateCell, trialValue);
if(hasSolution(game)){
solved = TRUE;
}else{
clearCell(game, candidateCell);
}
}
trialValue++;
}
}
return solved;
}
void readGame(sudokuGrid game){
int i = 0;
printf("Enter the grid: ");
scanf("%c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \
%c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c %c \
%c %c %c %c %c %c %c %c %c",\
&game[0], &game[1],&game[2], &game[3], &game[4], &game[5], &game[6], &game[7], &game[8],\
&game[9], &game[10],&game[11], &game[12], &game[13], &game[14], &game[15], &game[16], &game[17],\
&game[18], &game[19],&game[20], &game[21], &game[22], &game[23], &game[24], &game[25], &game[26],\
&game[27], &game[28],&game[29], &game[30], &game[31], &game[32], &game[33], &game[34], &game[35],\
&game[36], &game[37],&game[38], &game[39], &game[40], &game[41], &game[42], &game[43], &game[44],\
&game[45], &game[46],&game[47], &game[48], &game[49], &game[50], &game[51], &game[52], &game[53],\
&game[54], &game[55],&game[56], &game[57], &game[58], &game[59], &game[60], &game[61], &game[62],\
&game[63], &game[64],&game[65], &game[66], &game[67], &game[68], &game[69], &game[70], &game[71],\
&game[72], &game[73],&game[74], &game[75], &game[76], &game[77], &game[78], &game[79], &game[80]
);
}
void showGame(sudokuGrid game){
int i, j;
for(i = 0; i < 81; i++){
if((i) % 9 == 0){
printf("\n ");
for(j = 0; j < 37; j++){
printf("%c", 196);
}
printf("\n %c %c %c ", 179, game[i], 179);
}else{
printf("%c %c ", game[i], 179);
}
}
printf("\n ");
for(j = 0; j < 37; j++){
printf("%c", 196);
}
}
int isFull(sudokuGrid game){
int i;
for(i = 0; i < 81; i++){
if(game[i] == '.'){
return FALSE;
}
}
return TRUE;
}
int getEmptyCell(sudokuGrid game){
int i;
for(i = 0; i < 81; i++){
if(game[i] == '.'){
return i;
}
}
}
int isLegal(sudokuGrid game, int candidateCell, int trialValue){
int rowStart = (candidateCell/9)*9;
int columnStart = candidateCell % 9;
int i, k, temp;
int topLeft;
int topLeftElement;
for(i = rowStart; i < (rowStart +9); i++){
if((candidateCell != i) && (trialValue == game[i])){
return FALSE;
}
}
for(i = columnStart; i < 81; i+=9){
if((candidateCell != i) && (trialValue == game[i])){
return FALSE;
}
}
if(candidateCell >= 0 && candidateCell < 27){
topLeftElement = 0 + topLeftColumn(game, candidateCell);
}else if(candidateCell >= 27 && candidateCell < 54){
topLeftElement = 27 + topLeftColumn(game, candidateCell);
}else if(candidateCell >= 54 && candidateCell < 81){
topLeftElement = 54 + topLeftColumn(game, candidateCell);
}
for(k = 0; k < 3; k++){
int randCell = topLeftElement + k;
temp = checkBox(randCell, game, candidateCell, trialValue);
if(!temp){
return FALSE;
}
}
return TRUE;
}
void setCell(sudokuGrid game, int candidateCell, int trialValue){
game[candidateCell] = trialValue;
}
void clearCell(sudokuGrid game, int candidateCell){
game[candidateCell] = '.';
}
int topLeftColumn(sudokuGrid game, int candidateCell){
if(candidateCell%9 >= 0 && candidateCell%9 <3){
return 0;
}else if(candidateCell%9 >= 3 && candidateCell%9 <6){
return 3;
}else if(candidateCell%9 >= 6 && candidateCell%9 <9){
return 6;
}
}
int checkBox(int randCell, sudokuGrid game, int candidateCell, int trialValue){
int i;
for(i = randCell; i < (randCell + 20); i+=9){
if(i != candidateCell && game[i] == trialValue){
return FALSE;
}
}
return TRUE;
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Deals with top left corner of all nine smaller cells
if ((rowStart ==(0 || 27 ||54)) && (columnStart == (0 || 3 || 6))){
J = candiateCell;
for(J;J<(J+3);J++){
if((candidateCell != J) && (trialValue == game[J])){
return FALSE;
}
for(J+9;J<(J+12);J++){
if(((trialValue == game[J])){
return FALSE;
}
for(J+18;J<(J+21);J++){
if(((trialValue == game[J])){
return FALSE;
}
}
}
//Deals with top middle cell of all nine smaller cells
if ((rowStart ==(9 || 36 ||63)) && (columnStart == (1 || 4 || 7))){
J = candiateCell-1;
for(J;J<(J+3);J++){
if((candidateCell != J) && (trialValue == game[J])){
return FALSE;
for(J+9;J<(J+12);J++){
if(((trialValue == game[J])){
return FALSE;
for(J+18;J<(J+21);J++){
if(((trialValue == game[J])){
return FALSE;
}
}
//Deals with top right cell of all nine smaller cells
if ((rowStart ==(18 || 45 ||72)) && (columnStart == (2 || 5 || 8))){
J = candiateCell-2;
for(J;J<(J+3);J++){
if((candidateCell != J) && (trialValue == game[J])){
return FALSE;
for(J+9;J<(J+12);J++){
if(((trialValue == game[J])){
return FALSE;
for(J+18;J<(J+21);J++){
if(((trialValue == game[J])){
return FALSE;
}
}
}
return TRUE;
}
void setCell(sudokuGrid game, int candidateCell, int trialValue){
game[candidateCell] = trialValue;
}
void clearCell(sudokuGrid game, int candidateCell){
game[candidateCell] = '.';
}