nqueen challenge.py

Author: melophilecode

nqueen challenge.py

@@ -1,40 +1,69 @@
+
+
 global N
 N = 4
+
 def printSolution(board):
-    for i in range(N):
-        for j in range(N):
-            print (board[i][j],end=' ')
-        print()
+	for i in range(N):
+		for j in range(N):
+			print (board[i][j],end=' ')
+		print()
+
+
+
 def isSafe(board, row, col):
-    for i in range(col):
-        if board[row][i] == 1:
-            return False
-    for i, j in zip(range(row, -1, -1), range(col, -1, -1)):
-        if board[i][j] == 1:
-            return False
-        for i, j in zip(range(row, N, 1), range(col, -1, -1)):
-            if board[i][j] == 1:
-                return False
-        return True
+
+	for i in range(col):
+		if board[row][i] == 1:
+			return False
+
+
+	for i, j in zip(range(row, -1, -1), range(col, -1, -1)):
+		if board[i][j] == 1:
+			return False
+
+
+	for i, j in zip(range(row, N, 1), range(col, -1, -1)):
+		if board[i][j] == 1:
+			return False
+
+	return True
+
 def solveNQUtil(board, col):
-    if col >= N:
-        return True
-    for i in range(N):
-        if isSafe(board, i, col):
-            board[i][col] = 1
-        if solveNQUtil(board, col + 1) == True:
-            return True
-        board[i][col] = 0
-    return False
+	if col >= N:
+		return True
+
+
+	for i in range(N):
+
+		if isSafe(board, i, col):
+
+			board[i][col] = 1
+
+			if solveNQUtil(board, col + 1) == True:
+				return True
+
+
+			board[i][col] = 0
+
+
+	return False
+
 def solveNQ():
-    board = [[0, 0, 0, 0],
- [0, 0, 0, 0],
- [0, 0, 0, 0],
- [0, 0, 0, 0]
- ]
-    if solveNQUtil(board, 0) == False:
-        print ("Solution does not exist")
-        return False
-    printSolution(board)
-    return True
+	board = [ [0, 0, 0, 0],
+			[0, 0, 0, 0],
+			[0, 0, 0, 0],
+			[0, 0, 0, 0]
+			]
+
+	if solveNQUtil(board, 0) == False:
+		print ("Solution does not exist")
+		return False
+
+	printSolution(board)
+	return True
+
+
 solveNQ()
+
+