Merge pull request #8 from adhocore/code

Author: adhocore

.pylintrc

@@ -38,6 +38,9 @@ function-naming-style=snake_case
 good-names=i,
            j,
            k,
+           n,
+           s,
+           t,
            ex,
            Run,
            _

README.md

@@ -4,11 +4,13 @@ Just some (n|l)eet code solutions in Python.
 
 - [Container with max water](./containermaxwater.py)
 - [Eval reverse Polish notation](./evalrpn.py)
+- [Generate balanced parentheses](./generateparens.py)
 - [Group anagrams together](./groupanagrams.py)
 - [Is Anagram](./isanagram.py)
 - [Longest consecutive seq](./longestconsecutiveseq.py)
 - [Longest non repeat substr len](./longestsubstrlen.py)
 - [Product except self](./productexceptself.py)
+- [Queen attack](./queenattack.py)
 - [Stock max profit - single txn](./stockmaxprofit.py)
 - [String permutations as substring](./substrpermute.py)
 - [Three sum to zero](./threesumzero.py)

generateparens.py

@@ -7,14 +7,15 @@ def generate_parenthesis(num: int) -> list[str]:
     Space Complexity: O(1)
     Time Complexity:  O(n)
     """
+
     def generate(open_count: int, close_count: int, gen: str):
         if open_count == num and close_count == num:
             ans.append(gen)
             return
         if open_count < num:
-            generate(open_count + 1, close_count, gen + '(')
+            generate(open_count + 1, close_count, gen + "(")
         if open_count > close_count:
-            generate(open_count, close_count + 1, gen + ')')
+            generate(open_count, close_count + 1, gen + ")")
 
     ans = []
     generate(0, 0, "")

queenattack.py

@@ -0,0 +1,27 @@
+"""Number of postions a Queen can attack
+
+The number of positions in chess board that a Queen can attack in eight
+directions excluding obstacles.
+"""
+
+
+def queen_attack(
+    board_sz: int, queen_x: int, queen_y: int, obstacles: list[list[int]]
+) -> int:
+    """
+    Space Complexity: O(1)
+    Time Complexity:  O(8*n) => O(n)
+    """
+    ans = 0
+    dirs = [[0, 1], [0, -1], [1, 0], [-1, 0], [1, 1], [-1, -1], [1, -1], [-1, 1]]
+    obs = {(i[0], i[1]) for i in obstacles}
+    for dr in dirs:
+        x, y = queen_x + dr[0], queen_y + dr[1]
+        while 1 <= x <= board_sz and 1 <= y <= board_sz and (x, y) not in obs:
+            ans, x, y = ans + 1, x + dr[0], y + dr[1]
+    return ans
+
+
+if __name__ == "__main__":
+    print(queen_attack(5, 4, 3, [[5, 5], [4, 2], [2, 3]]))
+    # => 10