Add solution #1106

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,137 LeetCode solutions in JavaScript
+# 1,138 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -880,6 +880,7 @@
 1103|[Distribute Candies to People](./solutions/1103-distribute-candies-to-people.js)|Easy|
 1104|[Path In Zigzag Labelled Binary Tree](./solutions/1104-path-in-zigzag-labelled-binary-tree.js)|Medium|
 1105|[Filling Bookcase Shelves](./solutions/1105-filling-bookcase-shelves.js)|Medium|
+1106|[Parsing A Boolean Expression](./solutions/1106-parsing-a-boolean-expression.js)|Hard|
 1108|[Defanging an IP Address](./solutions/1108-defanging-an-ip-address.js)|Easy|
 1122|[Relative Sort Array](./solutions/1122-relative-sort-array.js)|Easy|
 1123|[Lowest Common Ancestor of Deepest Leaves](./solutions/1123-lowest-common-ancestor-of-deepest-leaves.js)|Medium|

solutions/1106-parsing-a-boolean-expression.js

@@ -0,0 +1,51 @@
+/**
+ * 1106. Parsing A Boolean Expression
+ * https://leetcode.com/problems/parsing-a-boolean-expression/
+ * Difficulty: Hard
+ *
+ * A boolean expression is an expression that evaluates to either true or false. It can be in
+ * one of the following shapes:
+ * - 't' that evaluates to true.
+ * - 'f' that evaluates to false.
+ * - '!(subExpr)' that evaluates to the logical NOT of the inner expression subExpr.
+ * - '&(subExpr1, subExpr2, ..., subExprn)' that evaluates to the logical AND of the inner
+ *   expressions subExpr1, subExpr2, ..., subExprn where n >= 1.
+ * - '|(subExpr1, subExpr2, ..., subExprn)' that evaluates to the logical OR of the inner
+ *   expressions subExpr1, subExpr2, ..., subExprn where n >= 1.
+ *
+ * Given a string expression that represents a boolean expression, return the evaluation of
+ * that expression.
+ *
+ * It is guaranteed that the given expression is valid and follows the given rules.
+ */
+
+/**
+ * @param {string} expression
+ * @return {boolean}
+ */
+var parseBoolExpr = function(expression) {
+  const stack = [];
+
+  for (const char of expression) {
+    if (char === ')') {
+      const operands = [];
+      while (stack[stack.length - 1] !== '(') {
+        operands.push(stack.pop());
+      }
+      stack.pop();
+      const operator = stack.pop();
+
+      if (operator === '!') {
+        stack.push(!operands[0]);
+      } else if (operator === '&') {
+        stack.push(operands.every(val => val));
+      } else if (operator === '|') {
+        stack.push(operands.some(val => val));
+      }
+    } else if (char !== ',') {
+      stack.push(char === 't' ? true : char === 'f' ? false : char);
+    }
+  }
+
+  return stack[0];
+};