Competitive programming questions

Day 28th Question: Merge k sorted linked lists and return it as one sorted list. Solution: https://www.prodevelopertutorial.com/merge-k-sorted-linked-lists-and-return-it-as-one-sorted-list/ ========================================= Day 37th Question: Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. Solution: https://www.prodevelopertutorial.com/given-a-matrix-of-m-x-n-elements-m-rows-n-columns-return-all-elements-of-the-matrix-in-spiral-order-in-cpp/ ========================================= Day 38th Question: Given an array of non-negative integers determine if you are able to reach the last index in C++ Solution: https://www.prodevelopertutorial.com/given-an-array-of-non-negative-integers-determine-if-you-are-able-to-reach-the-last-index-in-c/

Day 44 Question: Given a linked list, rotate the list to the right by k places, where k is non-negative. Example 1: Input: 1->2->3->4->5->NULL, k = 2 Output: 4->5->1->2->3->NULL Explanation: rotate 1 steps to the right: 5->1->2->3->4->NULL rotate 2 steps to the right: 4->5->1->2->3->NULL Example 2: Input: 0->1->2->NULL, k = 4 Output: 2->0->1->NULL Explanation: rotate 1 steps to the right: 2->0->1->NULL rotate 2 steps to the right: 1->2->0->NULL rotate 3 steps to the right: 0->1->2->NULL rotate 4 steps to the right: 2->0->1->NULL Difficulty: Medium

Hope you have solved previous questions, below are the solutions Day 32nd Question: Given a collection of numbers that might contain duplicates, return all possible unique permutations. Solution: https://www.prodevelopertutorial.com/given-a-collection-of-distinct-integers-return-all-possible-permutations-2/ ========================================= Day 33rd Question: Given an n x n 2D matrix rotate it by 90 degrees (clockwise) in C++ in place Solution: https://www.prodevelopertutorial.com/given-an-n-x-n-2d-matrix-rotate-it-by-90-degrees-clockwise-in-c-in-place/ ========================================= Day 34th Question: Group Anagrams in C++ Solution: https://www.prodevelopertutorial.com/group-anagrams-in-c/ ========================================= Day 35th Question: Rain water trapping in C++ Solution: https://www.prodevelopertutorial.com/rain-water-trapping-in-c/ ========================================= Day 36th Question: Implement pow(x, n), which calculates x raised to the power n (xn) in C++ Solution: https://www.prodevelopertutorial.com/implement-powx-n-which-calculates-x-raised-to-the-power-n-xn-in-c/

Day 43 Question: Write a program to find the node at which the intersection of two singly linked lists Sorted and Unsorted. For example, the following two linked lists: A: a1 → a2 ↘️ c1 → c2 → c3 ↗️ B: b1 → b2 → b3 begin to intersect at node c1. Notes: If the two linked lists have no intersection at all, return null. The linked lists must retain their original structure after the function returns. You may assume there are no cycles anywhere in the entire linked structure. Your code should preferably run in O(n) time and use only O(1) memory. Difficulty: Easy Companies Asked: Accolite, Microsoft, Amazon, D-E-Shaw, Goldman Sachs, MakeMyTrip, Qualcomm, Zopper

Day 42 Question: Given an input string (s) and a pattern (p), implement wildcard pattern matching with support for '?' and '*'. '?' Matches any single character. '*' Matches any sequence of characters (including the empty sequence). The matching should cover the entire input string (not partial). Note: s could be empty and contains only lowercase letters a-z. p could be empty and contains only lowercase letters a-z, and characters like ? or *. Example 1: Input: s = "aa" p = "a" Output: false Explanation: "a" does not match the entire string "aa". Example 2: Input: s = "aa" p = "*" Output: true Explanation: '*' matches any sequence. Example 3: Input: s = "cb" p = "?a" Output: false Explanation: '?' matches 'c', but the second letter is 'a', which does not match 'b'. Example 4: Input: s = "adceb" p = "*a*b" Output: true Explanation: The first '*' matches the empty sequence, while the second '*' matches the substring "dce". Example 5: Input: s = "acdcb" p = "a*c?b" Output: false Difficulty: Hard Companies Asked: Microsoft, Amazon, Ola Cabs, Walmart, InMobi, United Health Group

Day 41 Question: Given a positive integer n, generate a square matrix filled with elements from 1 to n2 in spiral order. Example: Input: 3 Output: [ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ] Difficulty: Medium Companies Asked: Microsoft JP Morgan Amazon

Day 40 Question: Reverse Linked List Reverse a singly linked list. Example: Input: 1->2->3->4->5->NULL Output: 5->4->3->2->1->NULL Follow up: A linked list can be reversed either iteratively or recursively. Could you implement both? Difficulty: Easy Quote: Be like a duck, paddling and working hard in the water, but what everyone sees is a smiling, calm face.

Day 39 Question: Given a collection of intervals, merge all overlapping intervals. Example 1: Input: [[1,3],[2,6],[8,10],[15,18]] Output: [[1,6],[8,10],[15,18]] Explanation: Since intervals [1,3] and [2,6] overlaps, merge them into [1,6]. Example 2: Input: [[1,4],[4,5]] Output: [[1,5]] Explanation: Intervals [1,4] and [4,5] are considerred overlapping. Difficulty: Medium Company asked: Google, Amazon

Day 31st Question: Given a collection of distinct integers, return all possible permutations. Solution: https://www.prodevelopertutorial.com/given-a-collection-of-distinct-integers-return-all-possible-permutations/ Please comment with your answers in the comment section of the above post.

Day 38 Question: Given an array of non-negative integers, you are initially positioned at the first index of the array. Each element in the array represents your maximum jump length at that position. Determine if you are able to reach the last index. Example 1: Input: [2,3,1,1,4] Output: true Explanation: Jump 1 step from index 0 to 1, then 3 steps to the last index. Example 2: Input: [3,2,1,0,4] Output: false Explanation: You will always arrive at index 3 no matter what. Its maximum jump length is 0, which makes it impossible to reach the last index. Difficulty: Medium Company asked: Moonfrog Labs, Amazon, Housing.com, Walmart Quote: The difference between ordinary and extraordinary is that little extra

Day 37 Question: Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. Example 1: Input: [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] Output: [1,2,3,6,9,8,7,4,5] Example 2: Input: [ [1, 2, 3, 4], [5, 6, 7, 8], [9,10,11,12] ] Output: [1,2,3,4,8,12,11,10,9,5,6,7] Difficulty: Medium Company asked: Paytm, Microsoft, Morgan Stanley, D-E-Shaw, Oracle, Snapdeal, MAQ Software, MakeMyTrip Quote: There is no substitute for hard work.

Day 36 Question: Implement pow(x, n), which calculates x raised to the power n (xn). Example 1: Input: 2.00000, 10 Output: 1024.00000 Example 2: Input: 2.10000, 3 Output: 9.26100 Example 3: Input: 2.00000, -2 Output: 0.25000 Explanation: 2-2 = 1/22 = 1/4 = 0.25 Note: -100.0 < x < 100.0 n is a 32-bit signed integer, within the range [−231, 231 − 1] Difficulty: Medium Companies Asked: Microsoft MakeMyTrip Quote: Opportunities are usually disguised as hard work, so most people don't recognize them.

Day 35 Question: Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining. Examples: Input: arr[] = {2, 0, 2} Output: 2 Structure is like below | | |_| We can trap 2 units of water in the middle gap. Input: arr[] = {3, 0, 0, 2, 0, 4} Output: 10 Structure is like below | | | | | | |__|_| We can trap "3*2 units" of water between 3 an 2, "1 unit" on top of bar 2 and "3 units" between 2 and 4. See below diagram also. Input: arr[] = [0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1] Output: 6 | | || | _|_||_|||||| Trap "1 unit" between first 1 and 2, "4 units" between first 2 and 3 and "1 unit" between second last 1 and last 2 Difficulty: HARD Companies Asked: Accolite Microsoft Amazon D-E-Shaw Payu Adobe Try with below Constraints: Time Complexity: O(n) Auxiliary Space: O(n) Motivational quote for the day: Once you have commitment, you need the discipline and hard work to get you there.

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Day 34 Question: Group Anagrams Given an array of strings, group anagrams together. Example: Input: ["eat", "tea", "tan", "ate", "nat", "bat"], Output: [ ["ate","eat","tea"], ["nat","tan"], ["bat"] ] Note: All inputs will be in lowercase. The order of your output does not matter. Difficulty: Medium Asked in companies: Amazon Microsoft Motivational quote for the day: There is no substitute for hard work. Never give up. Never stop believing. Never stop fighting. Note: I am aware that I am not providing solutions daily EOD as told, as I am facing some technical difficulties. Hopefully it will be resolved by Sunday.

Sorry, below is the correct Day 30th solution link: https://www.prodevelopertutorial.com/given-two-non-negative-integers-num1-and-num2-represented-as-strings-return-the-product-of-num1-and-num2-also-represented-as-a-string/

Day 33 Question: You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). Note: You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation. Example 1: Given input matrix = [ [1,2,3], [4,5,6], [7,8,9] ], rotate the input matrix in-place such that it becomes: [ [7,4,1], [8,5,2], [9,6,3] ] Difficulty: Medium Companies asked: Google Facebook Amazon ================================================================================ Hope you have solved Day 30th question. Day 30th Question: Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2, also represented as a string. Solution: https://www.prodevelopertutorial.com/given-a-collection-of-distinct-integers-return-all-possible-permutations/ Please comment with your answers in the comment section of the above post. Companies asked: Microsoft Flipkart Adobe Facebook

Hope you have solved Day 29th question. Day 29th Question: Given a collection of candidate numbers and a key, find all unique combinations in candidates where the candidate numbers sums to target Solution: https://www.prodevelopertutorial.com/given-a-collection-of-candidate-numbers-and-a-key-find-all-unique-combinations-in-candidates-where-the-candidate-numbers-sums-to-target/ Please comment with your answers in the comment section of the above post.

Day 32 Question: Given a collection of numbers that might contain duplicates, return all possible unique permutations. Example: Input: [1,1,2] Output: [ [1,1,2], [1,2,1], [2,1,1] ] Difficulty: Medium Companies asked: Microsoft Facebook Google

Hope you have solved Day 27th question. Day 27 Question: Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand. (i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]). You are given a target value to search. If found in the array return its index, otherwise return -1. You may assume no duplicate exists in the array. Your algorithm's runtime complexity must be in the order of O(log n). Solution: https://www.prodevelopertutorial.com/given-an-array-sorted-in-ascending-order-and-is-rotated-at-some-pivot-given-a-target-value-to-search-if-found-in-the-array-return-its-index/ Please comment with your answers in the comment section of the above post.