Merge pull request #157 from Srijan76-code/Sudoko-Solver

added sudoko solver

Author: admirerr

Python/backtracking/sudoko_solver.py

@@ -0,0 +1,72 @@
+def find_empty(board):
+    for i in range(len(board)):
+        for j in range(len(board[0])):
+            if board[i][j] == 0:
+                return (i, j)
+    return None
+
+def valid(board, num, pos):
+    for i in range(len(board[0])):
+        if board[pos[0]][i] == num and pos[1] != i:
+            return False
+            
+    for i in range(len(board)):
+        if board[i][pos[1]] == num and pos[0] != i:
+            return False
+
+    box_x = pos[1] // 3
+    box_y = pos[0] // 3
+
+    for i in range(box_y * 3, box_y * 3 + 3):
+        for j in range(box_x * 3, box_x * 3 + 3):
+            if board[i][j] == num and (i,j) != pos:
+                return False
+    return True
+
+def solve(board):
+    find = find_empty(board)
+    if not find:
+        return True
+    else:
+        row, col = find
+
+    for i in range(1,10):
+        if valid(board, i, (row, col)):
+            board[row][col] = i
+
+            if solve(board):
+                return True
+
+            board[row][col] = 0
+
+    return False
+
+def print_board(board):
+    for i in range(len(board)):
+        if i % 3 == 0 and i != 0:
+            print("- - - - - - - - - - - -")
+        for j in range(len(board[0])):
+            if j % 3 == 0 and j != 0:
+                print("|", end=" ")
+            if j == 8:
+                print(board[i][j])
+            else:
+                print(str(board[i][j]) + " ", end="")
+
+
+board = [
+    [7,8,0,4,0,0,1,2,0],
+    [6,0,0,0,7,5,0,0,9],
+    [0,0,0,6,0,1,0,7,8],
+    [0,0,7,0,4,0,2,6,0],
+    [0,0,1,0,5,0,9,3,0],
+    [9,0,4,0,6,0,0,0,5],
+    [0,7,0,3,0,0,0,1,2],
+    [1,2,0,0,0,7,4,0,0],
+    [0,4,9,2,0,6,0,0,7]
+]
+print("Original Sudoku Board:")
+print_board(board)
+solve(board)
+print("\nSolved Sudoku Board:")
+print_board(board)