This is Single Solutions For N-Queen and N-Queen II Problem, Just change the return and solution is ready.
For N Queen =====> return soultions
For N Queen II =====> return no_of_solutions
Please UpVote if you like this.
class Solution:
def solveNQueens(self, n: int) -> List[List[str]]:
rows = [0] * n
hills = [0] * (2n -1)
dales = [0] * (2n -1)
board = [["."] * n for _ in range(n)]
solutions = []
def free_to_place_queen(row, col):
if rows[col] or hills[row+col] or dales[row-col]:
return False
else :
return True
def place_queen_and_set_attack_zone(row, col):
board[row][col] = "Q"
rows[col] = 1
hills[row+col] = 1
dales[row-col] = 1
def remove_queen_and_release_attacking_zone(row, col):
board[row][col] = "."
rows[col] = 0
hills[row+col] = 0
dales[row-col] = 0
def backTrackNQueen(row, count):
for col in range(n):
if free_to_place_queen(row, col):
place_queen_and_set_attack_zone(row,col)
if row+1 == n:
count += 1
tmp = []
for i in range(n):
tmp.append(("").join(board[i]))
solutions.append(tmp)
else :
count = backTrackNQueen(row+1, count)
remove_queen_and_release_attacking_zone(row, col)
return count
no_of_solutions = backTrackNQueen(0,0)
return no_of_solutionsComments (0)