From 30c88a8a383e75a6dd4e0bc9a82ff2051c4c514b Mon Sep 17 00:00:00 2001
From: Angelos Chalaris <chalarangelo@gmail.com>
Date: Mon, 1 Jan 2018 19:03:47 +0200
Subject: [PATCH] Update and rename RPNSolver.md to solveRPN.md

---
 snippets/RPNSolver.md | 28 ----------------------------
 snippets/solveRPN.md  | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 28 deletions(-)
 delete mode 100644 snippets/RPNSolver.md
 create mode 100644 snippets/solveRPN.md

diff --git a/snippets/RPNSolver.md b/snippets/RPNSolver.md
deleted file mode 100644
index 4796d27cb..000000000
--- a/snippets/RPNSolver.md
+++ /dev/null
@@ -1,28 +0,0 @@
-### RPNSolver
-
-Solves the given reverse polish notation
-
-``` js
-const RPNSolver = RPN => {
-  const OPERATORS = {'*' : (a,b) => a * b, '+' : (a,b) => a + b, '-' : (a,b) => a - b, '/' : (a,b) => a / b, '**': (a,b) => a ** b}
-  const [stack,solve] = [[],RPN.replace(/\^/g,'**').split(/\s+/g).filter(el => !/\s+/.test(el) && el !== '')]
-  solve.forEach(symbol => {
-    if(!isNaN(parseFloat(symbol)) && isFinite(symbol)) {stack.push(symbol)}
-          else if (Object.keys(OPERATORS).includes(symbol)) {
-          const [a,b] = [stack.pop(),stack.pop()]
-          stack.push(OPERATORS[symbol](parseFloat(b),parseFloat(a)))
-        } else { throw `${symbol} is not a recognized symbol` }
-  }
-)
- if(stack.length === 1)  return stack.pop()
-  else  throw `${RPN} is not a proper RPN. Please check it and try again`
-}
-```
-
-```js
-RPNSolver('15 7 1 1 + - / 3 * 2 1 1 + + -'); // 5
-RPNSolver('3 5 6 + *'); //33
-RPNSolver('2 4 / 5 6 - *'); //-0.5
-RPNSolver('2 3 ^'); //8
-RPNSolver('2 3 ^'); //8
-```
diff --git a/snippets/solveRPN.md b/snippets/solveRPN.md
new file mode 100644
index 000000000..059c0ac36
--- /dev/null
+++ b/snippets/solveRPN.md
@@ -0,0 +1,34 @@
+### solveRPN
+
+Solves the given mathematical expression in [reverse polish notation](https://en.wikipedia.org/wiki/Reverse_Polish_notation).
+Throws appropriate errors if there are unrecognized symbols or the expression is wrong.
+
+Use a dictionary, `OPERATORS` to specify each operator's matching mathematical operation.
+Use `String.replace()` with a regular expression to replace `^` with `**`, `String.split()` to tokenize the string and `Array.filter()` to remove empty tokens.
+Use `Array.forEach()` to parse each `symbol`, evaluate it as a numeric value or operator and solve the mathematical expression.
+Numeric values are converted to floating point numbers and pushed to a `stack`, while operators are evaluated using the `OPERATORS` dictionary and pop elements from the `stack` to apply operations.
+
+``` js
+const solveRPN = rpn => {
+  const OPERATORS = {'*' : (a,b) => a * b, '+' : (a,b) => a + b, '-' : (a,b) => a - b, '/' : (a,b) => a / b, '**': (a,b) => a ** b};
+  const [stack,solve] = [[],rpn.replace(/\^/g,'**').split(/\s+/g).filter(el => !/\s+/.test(el) && el !== '')];
+  solve.forEach(symbol => {
+    if(!isNaN(parseFloat(symbol)) && isFinite(symbol)) {stack.push(symbol)}
+          else if (Object.keys(OPERATORS).includes(symbol)) {
+          const [a,b] = [stack.pop(),stack.pop()];
+          stack.push(OPERATORS[symbol](parseFloat(b),parseFloat(a)))
+        } else { throw `${symbol} is not a recognized symbol` }
+  }
+)
+ if(stack.length === 1)  return stack.pop()
+  else  throw `${rpn} is not a proper RPN. Please check it and try again`
+}
+```
+
+```js
+solveRPN('15 7 1 1 + - / 3 * 2 1 1 + + -'); // 5
+solveRPN('3 5 6 + *'); //33
+solveRPN('2 4 / 5 6 - *'); //-0.5
+solveRPN('2 3 ^'); //8
+solveRPN('2 3 ^'); //8
+```