Oct 20

2024-10-October-LeetCoding-Challenge/Parsing A Boolean Expression.py

@@ -0,0 +1,36 @@
+class Solution:
+    BOOL_MAP = {'t': True, 'f': False}
+
+    def parseBoolExpr(self, expression: str) -> bool:
+        stack = list()
+        for ch in expression:
+            if ch == ')':
+                vals = set()
+                while stack[-1] != '(':
+                    vals.add(stack.pop())
+                stack.pop()
+                operation = stack.pop()
+                if operation == '&':
+                    stack.append(all(vals))
+                elif operation == '|':
+                    stack.append(any(vals))
+                else:
+                    stack.append(not vals.pop())
+            elif ch != ',':
+                stack.append(self.BOOL_MAP.get(ch, ch))
+        return stack.pop()
+
+
+def main():
+    expression = '&(|(f))'
+    assert Solution().parseBoolExpr(expression) is False
+
+    expression = '|(f,f,f,t)'
+    assert Solution().parseBoolExpr(expression) is True
+
+    expression = '!(&(f,t))'
+    assert Solution().parseBoolExpr(expression) is True
+
+
+if __name__ == '__main__':
+    main()

2024-10-October-LeetCoding-Challenge/README.md

@@ -22,7 +22,7 @@
 | October 17 | [670. Maximum Swap](https://leetcode.com/problems/maximum-swap/) | Medium | Solved |
 | October 18 | [2044. Count Number of Maximum Bitwise-OR Subsets](https://leetcode.com/problems/count-number-of-maximum-bitwise-or-subsets/) | Medium | Unsolved |
 | October 19 | [1545. Find Kth Bit in Nth Binary String](https://leetcode.com/problems/find-kth-bit-in-nth-binary-string/) | Medium | Unsolved |
-| October 20 | []() |  |  |
+| October 20 | [1106. Parsing A Boolean Expression](https://leetcode.com/problems/parsing-a-boolean-expression/) | Hard | Solved |
 | October 21 | []() |  |  |
 | October 22 | []() |  |  |
 | October 23 | []() |  |  |
@@ -41,4 +41,4 @@
 | ---    | --- | --- | --- |
 | Easy   | 2 | 2 | 0 |
 | Medium | 16 | 8 | 8 |
-| Hard   | 1 | 0 | 1 |
+| Hard   | 2 | 1 | 1 |