added isapproxpalindrome.

src/bestBuyInterviewQuestions.js

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+// Given an array of SKUs return the number of duplicate SKUs.
+// i.e. fn([1234, 5678, 1234, 7777, 0000, 0000]) => 2
+// Since 1234 and 0000 are duplicates, the answer is 2
+// Can be solved in O(n), but there is an obvious O(n^2) solution
+
+// Given an array of SKUs, return the top k SKUs and their frequency.
+// i.e. fn(3, [12,
+// Can be done in O(n)
+// Write a function to flatten an array of arrays nested N levels deep.
+// fn([12, [34, 56], [78, [[9,10]],11]) = > [1,2,3,4,5,6,7,8,9,10]
+// Can be done in O(n)
+
+// Write a function to determine the maximum discount for a time period, given the following rules:
+// Day 1 – Day 5 => 10%
+// Day 2 – Day 7 => 5%
+// Day 4 – Day 6 => 20%
+// i.e. fn(4 (day)) => 10 + 5 + 20 = 35%
+
+// Given a list of products and their corresponding bundle prices. The customer wants to purchase N quantity of products from Best Buy. Provide a function which suggests the customer N quantity of products with the minimum price.
+// i.e
+// Quantity of Products = [10, 20, 30, 15, 25]
+// Price of product bundle = [100, 200, 120, 130, 165]
+// Customer wants to purchase 500 quantity of products – What is the minimum price?
+// This is an example of a “ Greedy Knapsack problem.”
+// Resource: https://en.wikipedia.org/wiki/Knapsack_problem

src/isApproxPalindrome.js

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+// Determine if a string of length S is a palindrome if you remove at most a single characters from that string.
+
+//Best Case: O(1) & Worst Case: O(2N)
+const isApproxPalindrome = (str, calledOnce = false) => {
+  if (str.length === 0) {
+    return true;
+  }
+  let result = isPalindrome(str);
+
+  if (result.isPalindrome) {
+    return true;
+  }
+
+  if (calledOnce) {
+    return false;
+  }
+
+  const { badIndex } = result;
+  str = str.slice(0, badIndex) + str.slice(badIndex + 1);
+
+  return isApproxPalindrome(str, true);
+};
+
+// O(1) Space & O(N) time
+const isPalindrome = str => {
+  const strArr = str.split("");
+  const strLength = str.length;
+  let result = {
+    isPalindrome: true,
+    badIndex: null
+  };
+
+  strArr.forEach((char, idx) => {
+    const correspondingChar = strArr[strLength - 1 - idx];
+    if (char !== correspondingChar) {
+      result = {
+        isPalindrome: false,
+        badIndex: idx
+      };
+    }
+  });
+  return result;
+};
+
+const data = ["abca", "aba", "abcd", "acba", ""]; // true, true, false, true, true
+
+data.forEach(testCase => {
+  console.log("isApproxPalindrome(testCase)", isApproxPalindrome(testCase));
+});

src/storeHours.js

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+/**
+ * You are assigned to build a function to figure out
+ * what to display for today's store hours based on current time.
+ *
+ * The backend engineer have an API at "/store-hours/44" to provide a list
+ * of open and close time for this week.
+ * Ex. { result : [
+ *          { open:"10-28-2018T12:00", close:"10-28-2018T20:00" },
+ *          { open:"10-29-2018T13:00", close:"10-29-2018T18:00" },
+ *          { open:"10-30-2018T10:00", close:"10-30-2018T19:00" },
+ *          { open:"10-31-2018T11:00", close:"10-31-2018T21:00" },
+ *          { open:"11-01-2018T12:00", close:"11-01-2018T20:00" },
+ *          { open:"11-02-2018T12:00", close:"11-02-2018T20:00" },
+ *          { open:"11-03-2018T12:00", close:"11-03-2018T20:00" },
+ *     ]}
+ *
+ * With those information, you have to figure out if you need to display
+ * one of those 3.
+ *   - 'Open on 11/03 until 10pm'
+ *   - 'Closed for the rest of day'
+ *   - 'Will open on 11/03 from 12pm to 10pm'
+ */
+
+function getStoreHoursText() {
+  // Step 1 : Fetching stored data from API
+  // Purpose : Check how we make ajax call, and the timing of receiving the data
+  const hours = fetchStoreHourData();
+  // Follow up : If you need to make 2 API calls for OPEN and CLOSE hours
+
+  // Step 2 : Loop thorugh the array with data conversion
+  // Purpose : Examine knowledge of looping and data manipulcation
+  const parsedHours = parseHours(hours);
+  // Follow up : slice() vs substring()
+  // https://stackoverflow.com/questions/2243824/what-is-the-difference-between-string-slice-and-string-substring
+
+  // Step 3 : Convert the marshalled data into human readable string
+  // Purpose : Testing String concatenation skill and conditional logic
+  const output = toHumanString(parsedHours);
+  //Follow up : what if we need to display Monday instead of 11/03
+
+  return output;
+}
+
+getStoreHoursText();