Competitive Programming

================================================ Hope you guys have solved Question 12. Question 12: Zig-zag conversion: Given a string, and number of rows, write the string in zigzag pattern. Write your thoughts in the comment section of the link below: https://www.prodevelopertutorial.com/given-a-string-and-number-of-rows-write-the-string-in-zigzag-pattern/ Difficulty: Medium Company: paypal ================================================ Todays Question 13: Longest Palindromic Substring Given a string, find the longest palindromic string in that array. A palindromic string will give the same string when read reverse. Example: “aba” reverse is “aba” hence is a palindromic string. Input: ashdkabajjseiw Output: aba Please try to solve in O(n^2). Difficulty: Medium Company: Microsoft, groupon, accolite Link for todays question: https://www.prodevelopertutorial.com/longest-palindromic-substring-with-detailed-explanation-and-solution-in-c/ ================================================

Question 12: Zig-zag conversion: Given a string, and number of rows, write the string in zigzag pattern. Write your thoughts in the comment section of the link below: https://www.prodevelopertutorial.com/given-a-string-and-number-of-rows-write-the-string-in-zigzag-pattern/ Difficulty: Medium Company: paypal Quick Update: Till now I was posting questions in random order of difficulty. But from now on, from monday to saturday I shall be posting questions of difficulty easy to medium [mostly medium]. On sunday I shall be posting a hard question. These hard question will take lot of time to complete. And sunday most of them are free try to understand and come up with a solution. Any feedback please let me know.

I have given my contact details are in the Channel info.

Public poll: I am planning to create a discussion forum in the website so that you guys can hangout there, discuss the problems and solutions, request for tutorials, and share your interview experience. I would like to know if it would be helpful for you guys. Please let me know personally, so that, I shall work on it at the earliest.

Hope you guys have solved question 8 and question 9. Click on the below link to know the solution. Please write your solution in the comment section of the post. Question 10: Given an array, find all the repeated elements. https://www.prodevelopertutorial.com/given-an-array-find-all-the-repeated-elements-in-c-language/ Question 11: Given an integer value, convert it into roman number. https://www.prodevelopertutorial.com/given-an-integer-value-convert-it-into-roman-number/ Let me know your thoughts in the comment section of the post below.

Question 10 ================= Given an array, find all the repeated elements. Problem Description: Given a positive integer array, find all the elements that have been repeated and display them. Example: Input: {1, 3, 2, 7, 5, 1, 8, 3, 6, 10} Output: 1, 3 Difficulty: Medium Asked in company: Amazon, paytm Question 11: ================= Given an integer value, convert it into roman number. Problem Explanation: Roman numbers are represented by below characters: I 1 V 5 X 10 L 50 C 100 D 500 M 1000 IV 4 IX 9 XL 40 XC 100 CD 400 CM 900 Example: Input: 3 Output: "III" Input: 58 Output: "LVIII" Difficulty: Medium Company: Microsoft, facebook, amazon

Hope you guys have solved question 8 and question 9. Click on the below link to know the solution. Please write your solution in the comment section of the post. Question 8: Given an unsorted array, and a key. Find 2 elements such that the difference between the elements is equal to the key. Solution: https://www.prodevelopertutorial.com/given-an-unsorted-array-and-a-key-find-2-elements-such-that-the-difference-between-the-elements-is-equal-to-the-key/ Question 9: Given an unsorted integer array, find the smallest missing positive integer. Solution: https://www.prodevelopertutorial.com/given-an-unsorted-integer-array-find-the-smallest-missing-positive-integer/

Question 8 : ================ Given an unsorted array, and a key. Find 2 elements such that the difference between the elements is equal to the key. Example: {4, 2, 5, 8, 21, 34, 10} key = 24 Output: Pair found (34, 10) Difficulty: Easy https://www.prodevelopertutorial.com/given-an-unsorted-array-and-a-key-find-2-elements-such-that-the-difference-between-the-elements-is-equal-to-the-key/ As question 8 is easy solve below question 9 also today. Question 9 : =================== Given an unsorted integer array, find the smallest missing positive integer. Example 1: Input: [ 2, 3, -1, -2] Output: 1 Example 2: Input: [5, 6, 7, 8, 9] Output: 1 Your algorithm should run in O(n) time and uses constant space. Integer starts from 1. Hence consider the smallest +ve integer is 1. https://www.prodevelopertutorial.com/given-an-unsorted-integer-array-find-the-smallest-missing-positive-integer/ Difficulty: hard

Hope you guys have solved day 7 question. Click on the below link to know the solution. Please write your solution in the comment section of the post. https://www.prodevelopertutorial.com/given-an-unsorted-array-find-the-list-difference-between-the-element-pairs-display-all-the-pairs-present/

Day 7 Question: Given an unsorted array, find the list difference between the element pairs. Display all the pairs present. Problem Statement: Given an unsorted array, list all the pairs with a least difference. Example: Input: {5, 4, 3, 2, 1} Output: {1, 2}, {2, 3}, {3, 4}, {4, 5}. Difficulty: Easy Postyour solution in the comment section of the below link: https://www.prodevelopertutorial.com/given-an-unsorted-array-find-the-list-difference-between-the-element-pairs-display-all-the-pairs-present/ Pro Tip: If you are not able to solve the problem, when I give you the solution, try to compile and run the program. Try it with different inputs and understand the program output.

Hope you guys have solved day 6 question. Click on the below link to know the solution. Please write your solution in the comment section of the post. https://www.prodevelopertutorial.com/given-an-unsorted-array-find-the-minimum-difference-between-2-elements/

Day 6 Question: Given an unsorted array, find the minimum difference between 2 elements. Problem Explanation: Given an unsorted array, the output should be the minimum difference between the elements and the elements itself. Example: {6, 10, 5, 42, 43, 1, 2} output: The minimum difference between is 1 the elements are 1 and 2. Difficulty: Easy Asked in company: Amazon Note: The solutions will be provided in C or C++. I encourage you to please try out in other languages and write the solution in the comment section of the link below. https://www.prodevelopertutorial.com/given-an-unsorted-array-find-the-minimum-difference-between-2-elements/

Hope you guys have solved todays question. Click on the below link to know the solution. Please write your solution in the comment section of the post. https://www.prodevelopertutorial.com/given-an-array-the-difference-between-the-elements-is-one-find-if-the-key-element-is-present-or-not/ I appreciate that some of you guys have written the logic in comment section of the post. Keep up the good work. It will definately improve your programming skills.

Day 5 Question: Given an array, the difference between the elements is one, find if the “key” element is present or not. Example: Array: {5, 6, 7, 6, 5, 4, 3, 4, 5, 6} Key: 4 Output: The element 4 is found at the index 6. Difficulty: Easy Note: This answer can be solved by iterating throught all the array elements as a brute force method. But that answer is not acceptable. Please solve by different logic. Post your answers in the comment section of the link below. Night I shall provide you with answer. https://www.prodevelopertutorial.com/given-an-array-the-difference-between-the-elements-is-one-find-if-the-key-element-is-present-or-not/

Hope you guys have solved todays question. Click on the below link to know the solution. Please write your solution in the comment section of the post. https://www.prodevelopertutorial.com/sort-an-array-of-0s-1s-and-2s-in-c/

Day 4 Question: Sort an array of 0s, 1s and 2s in C Problem Description: Given an array of elements consisting of 0, 1, 2. Sort the array. Example: {1, 2, 0, 0, 1, 2, 1} Output: {0, 0, 1, 1, 1, 2, 2} Difficulty: Easy Asked in company: Amazon

Hope you guys have solved todays question. Click on the below link to know the solution. Please write your solution in the comment section of the post. https://www.prodevelopertutorial.com/count-the-number-of-ways-a-baby-can-reach-the-nth-stair-taking-1-or-2-steps-at-a-time-in-c-language/

Day 3 Question: Count the number of ways a baby can reach the n’th stare taking 1 or 2 steps at a time in C language. Problem Description: A baby wants to climb the stairs. It can take single step at a time or take 2 steps at a time. Or it can take combination of 1 and 2 steps at a time. Given that there are N stairs, find the number of ways the baby can reach the top of the stairs. Difficulty: Easy Asked in company: Amazon, Intel

Hope you guys have solved todays question. Click on the below link to know the solution. Please write your solution in the comment section of the post. https://www.prodevelopertutorial.com/given-two-non-empty-linked-list-with-non-negative-numbers-and-numbers-are-stored-in-reverse-order-having-single-digit-add-the-two-list-and-return-the-result-as-a-linked-list/

Day 2 Question: You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list. You may assume the two numbers do not contain any leading zero, except the number 0 itself. Example Input: (2 -> 4 -> 3) + (5 -> 6 -> 4) Output: 7 -> 0 -> 8 Explanation: 342 + 465 = 807. Difficulty: Medium Asked in company: Amazon