Add boolean eval

.gitignore

@@ -1 +1,2 @@
 node_modules
+.DS_Store

08_recursion_and_dynamic_programming/14_booleanEvaluation.js

@@ -0,0 +1,18 @@
+/*
+  Given a boolean expression consisting of the symbols 0 (false), 1(true),
+  & (AND), | (OR), and ^(XOR), and a desired boolean result value 'result',
+  implement a function to count the number of ways of parenthesizing the expression such
+  that it evaluates to 'result'
+
+  E.g.
+  countEval('1^0|0|1', false) -> 2
+  countEval('0&0&0&1^1|0', true) -> 10
+*/
+
+'use strict';
+
+function countEval() {
+  // Your code here
+}
+
+module.exports = countEval;

08_recursion_and_dynamic_programming/14_booleanEvaluation.test.js

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+'use strict';
+
+const assert = require('chai').assert;
+const countEval = require('./14_booleanEvaluation');
+
+describe('recursion and dynamic programming', function() {
+  describe('boolean evaluation', function() {
+    it('should return the number of ways of parenthesizing an expression', function() {
+      const expression = '1^0|0|1';
+      const result = false;
+      assert.equal(countEval(expression, result), 2);
+    })
+  })
+})