Question 52

Author: shubhamkumar27

52. N-Queens II.py

@@ -22,3 +22,35 @@
   ".Q.."]
 ]
 '''
+
+
+class Solution:
+    def totalNQueens(self, n: int) -> int:
+        result = []
+        queensColumn = [-1]*n
+        placeQueens(0, queensColumn, n, result)
+        return len(result)
+
+
+def isValidPos(queensColumn, col, row):
+    valid = True
+    for i in range(row):
+
+        if queensColumn[i]==col:
+            valid = False
+
+        if abs(col-queensColumn[i])==abs(row-i):
+            valid = False
+
+    return valid
+
+
+def placeQueens(row, queensColumn, n, result):
+    if row==n:
+        result.append(1)
+        return
+    
+    for i in range(n):
+        if isValidPos(queensColumn, i, row):
+            queensColumn[row] = i
+            placeQueens(row+1, queensColumn, n, result)