From 00eed614d37f69ac0688733ef6fc0c9c56086da5 Mon Sep 17 00:00:00 2001
From: Sarthak Jain <61319250+thesarthakjain@users.noreply.github.com>
Date: Mon, 4 Oct 2021 12:31:24 +0530
Subject: [PATCH] Added sudoku.py

---
 PYTHON/sudoku.py | 81 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 PYTHON/sudoku.py

diff --git a/PYTHON/sudoku.py b/PYTHON/sudoku.py
new file mode 100644
index 00000000..54865544
--- /dev/null
+++ b/PYTHON/sudoku.py
@@ -0,0 +1,81 @@
+board = [[9,0,8,0,0,0,2,0,3],
+    [0,4,0,0,9,0,0,6,0],
+    [7,0,0,8,0,1,0,0,4],
+    [6,0,0,4,0,9,0,0,0],
+    [8,0,0,5,0,6,0,0,1],
+    [0,0,0,3,0,2,0,0,0],
+    [3,0,0,2,0,8,0,0,9],
+    [0,8,0,0,6,0,0,4,0],
+    [1,0,2,0,0,0,5,0,6]]
+
+
+
+def print_board(bo):
+    for i in range(9):
+        if i % 3 == 0 and i != 0:
+            print('- - - - - - - - - - - -')
+        for j in range(9):
+            if j % 3 == 0 and j != 0:
+                print(' | ',end='')
+            print(bo[i][j],end = ' ')
+        print()
+
+
+
+def find_empty(bo):
+    for i in range(9):
+        for j in range(9):
+            if bo[i][j] == 0:
+                return(i,j)
+    else:
+        return (None)
+
+
+
+def valid(bo,num,pos):
+    #row
+    for j in range(9):
+        if bo[pos[0]][j] == num and j != pos[1]:
+            return (False)
+
+    #column
+    for i in range(9):
+        if bo[i][pos[1]] == num and i!=pos[0] :
+            return (False)
+
+    #subgrid
+    x_sub = int(pos[0]/3)
+    y_sub = int(pos[1]/3)
+    for i in range(x_sub * 3 , (x_sub * 3) + 3):
+        for j in range(y_sub * 3 , (y_sub*3) + 3):
+            if bo[i][j] == num and (i,j)!=pos:
+                return(False)
+
+    return (True)
+
+
+
+def solve(bo):
+    find = find_empty(bo)
+    if not find :
+        return (True)
+    else :
+        x,y = find
+
+    for i in range(1,10):
+        if valid(bo,i,(x,y)):
+            bo[x][y] = i
+
+            if solve(bo):
+                return (True)
+
+            bo[x][y] = 0
+
+    return(False)
+
+
+
+print_board(board)
+solve(board)
+print('\nSolution :\n')
+print_board(board)