Enhanced Sudoku Solver

7 Sudoku Solver/sudoku.c

@@ -1,6 +1,16 @@
+#define _POSIX_C_SOURCE 199309L
+#include <time.h>
 #include <stdio.h>
+#include <stdlib.h>
 
-int puzzle[9][9] = {
+
+void print_puzzle(int puzzle[9][9]);
+int valid_move(int puzzle[9][9], int x, int y, int val);
+int solve_puzzle(int puzzle[9][9], int x, int y);
+int valid_puzzle(int puzzle[9][9]);
+void clear_screen();
+
+int sudoku[9][9] = {
   {3,0,0,0,2,0,0,7,0},
   {9,0,0,5,0,0,0,1,4},
   {0,1,6,3,7,0,0,0,8},
@@ -12,97 +22,166 @@ int puzzle[9][9] = {
   {7,3,1,0,8,2,0,0,0},
 };
 
-void print_puzzle(int puzzle[9][9]);
-int valid_move(int puzzle[9][9], int row, int col, int val);
-int solve_puzzle(int puzzle[9][9], int row, int col);
-
-int main() {
-  printf("\n\tWelcome to SUDOKU Solver !!!");
-  printf("\n\nOriginal Puzzle:");
-  print_puzzle(puzzle);
-  if (solve_puzzle(puzzle, 0, 0)) {
-    printf("\n The puzzle is solved: ");
-    print_puzzle(puzzle);
-  } else {
-    printf("\n This puzzle is not Solvable\n");
-  }
-  return 0;
-}
+struct timespec ts;
 
-int solve_puzzle(int puzzle[9][9], int row, int col) {
+int main(void)
+{
+    ts.tv_sec  = 0;
+    ts.tv_nsec = 50000000;
 
-  if (col == 9) {
-    if (row == 8) {
-      return 1; // Puzzle solved
+    printf("Original Puzzle : \n");
+    print_puzzle(sudoku);
+    if (valid_puzzle(sudoku))
+    {
+        if (solve_puzzle(sudoku, 0, 0))
+        {
+            printf("The solved puzzle is : \n");
+            print_puzzle(sudoku);
+        }
+        else
+        {
+            printf("OOPS..The puzzle is not solvable :(\n");
+        }
     }
-    row++;
-    col = 0;
-  }
-
-  if (puzzle[row][col] > 0) {
-    return solve_puzzle(puzzle, row, col + 1);
-  }
-
-  for (int i = 1; i <= 9; i++) {
-    if (valid_move(puzzle, row, col, i)) {
-      puzzle[row][col] = i;
-      if (solve_puzzle(puzzle, row, col + 1)) {
-        return 1;
-      }
-      puzzle[row][col] = 0;
+    else
+    {
+        printf("\nSorry, the given puzzle itself is wrong :)\n");
     }
-  }
-  return 0;
+
+    return 0;
 }
 
-int valid_move(int puzzle[9][9], int row, int col, int val) {
 
-  // valid row
-  for (int i = 0; i < 9; i++) {
-    if (puzzle[row][i] == val) {
-      return 0;
+int solve_puzzle(int puzzle[9][9], int x, int y)
+{
+    nanosleep(&ts, NULL);
+    clear_screen();
+    print_puzzle(puzzle);
+    if (x == 9)
+    {
+        if (y == 8)
+        {
+            return 1;
+        }
+        y = y + 1;
+        x = 0;
+    }
+
+    if (puzzle[y][x] > 0)
+    {
+        return solve_puzzle(puzzle, x + 1, y);
     }
-  }
 
-  // valid column
-  for (int i = 0; i < 9; i++) {
-    if (puzzle[i][col] == val) {
-      return 0;
+    for (int i = 1; i <= 9; i++)
+    {
+        if (valid_move(sudoku, x, y, i))
+        {
+            sudoku[y][x] = i;
+            if (solve_puzzle(sudoku, x + 1, y))
+            {
+                return 1;
+            }
+            sudoku[y][x] = 0;
+        }
     }
-  }
-
-  // valid square
-  int r = row - row % 3;
-  int c = col - col % 3;
-  for (int i = 0; i < 3; i++) {
-    for (int j = 0; j < 3; j++) {
-      if (puzzle[r+i][c+j] == val) {
-        return 0;
-      }
+    return 0;
+}
+
+
+int valid_move(int puzzle[9][9], int x, int y, int val)
+{
+    for (int i = 0; i < 9; i++)
+    {
+        if (puzzle[y][i] == val)
+        {
+            return 0;
+        }
+
+        if (puzzle[i][x] == val)
+        {
+            return 0;
+        }
     }
-  }
 
-  return 1;
+    int c = x - x % 3;
+    int r = y - y % 3;
+    for (int i = 0; i < 3; i++)
+    {
+        for (int j = 0; j < 3; j++)
+        {
+            if (puzzle[r + i][c + j] == val)
+            {
+                return 0;
+            }
+        }
+    }
+    return 1;
 }
 
-void print_puzzle(int puzzle[9][9]) {
-  printf("\n+-------+-------+-------+");
-  for (int row = 0; row < 9; row++) {
-    if (row % 3 == 0 && row != 0) {
-      printf("\n|-------+-------+-------|");
+
+int valid_puzzle(int puzzle[9][9])
+{
+    for (int i =0; i<9; i++)
+    {
+        for (int j = 0; j<9; j++)
+        {
+            if (puzzle[i][j]==0)
+            {
+                continue;
+            }
+            else
+            {
+                int temp = puzzle[i][j];
+                puzzle[i][j] = 0;
+
+                if (valid_move(puzzle, j, i, temp) == 0)
+                {
+                    return 0;
+                }
+
+                puzzle[i][j] = temp;
+            }
+        }
     }
-    printf("\n");
-    for (int col = 0; col < 9; col++) {
-      if (col % 3 == 0) {
-        printf("| ");
-      }
-      if (puzzle[row][col] != 0) {
-        printf("%d ", puzzle[row][col]);
-      } else {
-        printf("  ");
-      }
+    return 1;
+}
+
+
+void print_puzzle(int puzzle[9][9])
+{
+    printf("\n+-------+-------+-------+\n");
+    for (int i = 0; i < 9; i++)
+    {
+        if (i == 3 || i == 6)
+        {
+            printf("|-------+-------+-------|\n");
+        }
+        for (int j = 0; j < 9; j++)
+        {
+            if (j % 3 == 0)
+            {
+                printf("| ");
+            }
+            if (puzzle[i][j] != 0)
+            {
+                printf("%d ", puzzle[i][j]);
+            }
+            else
+            {
+                printf("  ");
+            }
+        }
+        printf("|");
+        printf("\n");
     }
-    printf("|");
-  }
-  printf("\n+-------+-------+-------+\n");
-}
+    printf("+-------+-------+-------+\n");
+}
+
+void clear_screen()
+{
+    #ifdef _WIN32
+        system("cls");
+    #else
+        system("clear");
+    #endif
+}