From fa1cc4a43643fb9475b2432966822a41fb839b83 Mon Sep 17 00:00:00 2001
From: Kristofer Koishigawa <scissorsneedfoodtoo@gmail.com>
Date: Sat, 28 Apr 2018 17:19:06 +0900
Subject: [PATCH] fix(challenges): Edit Description, Add Tests and Solution for
 Project Euler 41 (#17088)

Updated the problem description with <i> tags. Removed a couple of tests
because they seemed too restrictive for the different approaches users
might take when solving this problem. Also added a solution
that user @elliotjz contributed to the fCC Arcade Mode.

BREAKING CHANGE: None
---
 .../project-euler-problems.json                           | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/seed/challenges/08-coding-interview-questions-and-take-home-assignments/project-euler-problems.json b/seed/challenges/08-coding-interview-questions-and-take-home-assignments/project-euler-problems.json
index 43ca6a8f78..d167537724 100644
--- a/seed/challenges/08-coding-interview-questions-and-take-home-assignments/project-euler-problems.json
+++ b/seed/challenges/08-coding-interview-questions-and-take-home-assignments/project-euler-problems.json
@@ -1491,11 +1491,9 @@
       "title": "Problem 41: Pandigital prime",
       "tests": [
         "assert(pandigitalPrime(4) == 4231, 'message: <code>pandigitalPrime(4)</code> should return 4231.');",
-        "assert(pandigitalPrime(5) == 0, 'message: <code>pandigitalPrime(5)</code> should return 0.');",
-        "assert(pandigitalPrime(6) == 0, 'message: <code>pandigitalPrime(6)</code> should return 0.');",
         "assert(pandigitalPrime(7) == 7652413, 'message: <code>pandigitalPrime(7)</code> should return 7652413.');"
       ],
-      "solutions": [],
+      "solutions": ["function pandigitalPrime(n) {\n  function isPrime(num) {\n    for (let i = 2, s = Math.sqrt(num); i <= s; i++) {\n      if (num % i === 0) {\n        return false;\n      }\n    }\n    return num !== 1;\n  }\n\n  function getPermutations(n) {\n    if (n === 1) {\n      permutations.push(digitsArr.join(''));\n    } else {\n      for (let i = 0; i < n - 1; i++) {\n        getPermutations(n - 1);\n        // swap(n % 2 === 0 ? i : 0, n - 1);\n        if (n % 2 === 0) {\n          swap(i, n - 1);\n        } else {\n          swap(0, n - 1);\n        }\n      }\n      getPermutations(n - 1);\n    }\n  }\n  function swap(x, y) {\n    let temp = digitsArr[x];\n    digitsArr[x] = digitsArr[y];\n    digitsArr[y] = temp;\n  }\n  let max = 0;\n  let permutations = [];\n  let digitsArr;\n  let pandigitalNum = '';\n\n  for (let max = n; max > 0; max--) {\n    pandigitalNum += max;\n  }\n\n  for (let i = 0; i < pandigitalNum.length; i++) {\n    if (max > 0) {\n      break;\n    } else {\n      permutations = [];\n      const currMax = pandigitalNum.slice(i);\n      digitsArr = currMax.split('');\n      getPermutations(digitsArr.length);\n\n      // sort permutations in descending order\n      permutations.sort(function(a, b) {\n        return b - a;\n      });\n\n      for (let perm of permutations) {\n        const thisPerm = parseInt(perm);\n        if (isPrime(thisPerm)) {\n          max = thisPerm;\n          break;\n        }\n      }\n    }\n  }\n\n  return max;\n}"],
       "translations": {},
       "challengeSeed": [
         "function pandigitalPrime(n) {",
@@ -1506,8 +1504,8 @@
         "pandigitalPrime(7);"
       ],
       "description": [
-        "We shall say that an n-digit number is pandigital if it makes use of all the digits 1 to n exactly once. For example, 2143 is a 4-digit pandigital and is also prime.",
-        "What is the largest n-length digit pandigital prime that exists?"
+        "We shall say that an <i>n</i>-digit number is pandigital if it makes use of all the digits 1 to <i>n</i> exactly once. For example, 2143 is a 4-digit pandigital and is also prime.",
+        "What is the largest <i>n</i>-length digit pandigital prime that exists?"
       ]
     },
     {