Interview Prep Kit #interview

INTERVIEW_PREP_KIT.md

BASICS

• Factorial: https://github.com/theodesp/go-hackerearth/blob/master/basic-programming/Factorial.go
• Get Prime Numbers: https://github.com/theodesp/go-hackerearth/blob/master/basic-programming/PrimeNumber.go
• Count bits in number:
  • https://www.geeksforgeeks.org/count-set-bits-in-an-integer/
  • https://github.com/theodesp/go-hackerearth/blob/master/basic-programming/CountBits.go

ARRAYS

• Transpose Matrix:
  • https://github.com/theodesp/go-hackerearth/blob/master/data-structures/TransposeMatrix.go
  • https://www.geeksforgeeks.org/program-to-find-transpose-of-a-matrix/
• Rotate Left Array:
  • https://www.geeksforgeeks.org/array-rotation/
  • https://github.com/theodesp/go-hackerrank/blob/master/classics/arrayRotation.go
• Pascals Triange:
  • https://leetcode.com/problems/pascals-triangle/discuss/394970/Java-solution-explained-using-DP-(Top-down-Bottom-up-Recursive-Iterative)-0ms
  • https://www.geeksforgeeks.org/pascal-triangle/
  • https://github.com/theodesp/go-leetcode/blob/master/array/pascalTriangle.go
• K-th Element of Two Sorted Arrays
  • https://github.com/theodesp/go-leetcode/blob/master/array/kthSmallestElementTwoSortedArrays.go
  • https://www.geeksforgeeks.org/k-th-element-two-sorted-arrays/

RECURSION:

• Print all permutations of array
  • https://www.codesdope.com/blog/article/generating-permutations-of-all-elements-of-an-arra/
  • https://leetcode.com/problems/permutations/
  • https://github.com/theodesp/go-leetcode/blob/master/array/arrayPermutations.go
• Find Kth largest/smallers element in unsorted array
  • https://leetcode.com/problems/kth-largest-element-in-an-array/
  • https://www.geeksforgeeks.org/kth-smallestlargest-element-unsorted-array/
  • https://github.com/theodesp/go-leetcode/blob/master/array/kthLargestElement.go

HASHTABLES

• Check if two strings are anagrams:
  • https://www.geeksforgeeks.org/check-whether-two-strings-are-anagram-of-each-other/
  • https://github.com/theodesp/go-hackerrank/blob/master/classics/makingAnagrams.go

QUEUES

• Implement Queue using 2 stacks:
  • https://github.com/theodesp/go-leetcode/blob/master/queue/QueueUsingStack.go
  • https://www.geeksforgeeks.org/queue-using-stacks/

STACKS

• Find balanced brackets:
  • https://www.geeksforgeeks.org/check-for-balanced-parentheses-in-an-expression/
  • https://github.com/theodesp/go-hackerearth/blob/master/data-structures/BalancedBrackets.go
• Implement Stack using queues:
  • https://github.com/theodesp/go-leetcode/blob/master/stack/StackUsingQueues.go
  • https://www.geeksforgeeks.org/implement-stack-using-queue/
• Implement a Sortable Stack
  • https://github.com/theodesp/go-leetcode/blob/master/stack/SortableStack.go
  • https://www.geeksforgeeks.org/sort-stack-using-temporary-stack/

LISTS

• Implement Single Linked List:
  • https://www.geeksforgeeks.org/linked-list-set-2-inserting-a-node/
  • https://leetcode.com/problems/design-linked-list/
• Implement Double Linked List:
  • https://github.com/theodesp/go-leetcode/blob/master/list/DoubleLinkedList.go
  • https://www.geeksforgeeks.org/doubly-linked-list/
• Find middle element:
  • https://www.geeksforgeeks.org/write-a-c-function-to-print-the-middle-of-the-linked-list/
  • https://github.com/theodesp/go-leetcode/blob/master/list/findMiddleElement.go
• Reverse a list:
  • https://github.com/theodesp/go-leetcode/blob/master/list/reverseList.go
  • https://www.geeksforgeeks.org/reverse-a-linked-list/
• Remove duplicates from linked list
  • https://www.geeksforgeeks.org/remove-duplicates-from-an-unsorted-linked-list/
  • https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/

BACKTRACKING

• NQeens:
  • https://www.geeksforgeeks.org/n-queen-problem-backtracking-3/
  • https://github.com/theodesp/go-hackerearth/blob/master/basic-programming/NQueens.go

TRIES

• Implementation:
  • https://github.com/theodesp/go-leetcode/blob/master/trie/trie.go
  • https://www.geeksforgeeks.org/trie-insert-and-search/
• Find all words in Matrix
  • https://github.com/theodesp/go-leetcode/blob/master/trie/wordSearch.go

HEAPS

• Implementation
  • https://github.com/theodesp/go-leetcode/blob/master/heap/heap.go
  • https://www.geeksforgeeks.org/binary-heap/
• Find median in stream of numbers
  • https://www.geeksforgeeks.org/median-of-stream-of-integers-running-integers/

HASH TABLE

• Implementation
  • https://www.geeksforgeeks.org/hashing-set-3-open-addressing/
  • https://github.com/theodesp/go-leetcode/blob/master/hashTable/linearProbing.go

GRAPHS

• Undirected Graph
  • https://github.com/theodesp/go-leetcode/blob/master/graphs/undirectedGraph.go
  • https://www.geeksforgeeks.org/graph-and-its-representations/
• Directed Graph
  • https://github.com/theodesp/go-leetcode/blob/master/graphs/directedGraph.go
• BFS
  • https://www.geeksforgeeks.org/breadth-first-search-or-bfs-for-a-graph/
• DFS
  • https://www.geeksforgeeks.org/depth-first-search-or-dfs-for-a-graph/
  • https://github.com/theodesp/go-leetcode/blob/master/graphs/undirectedGraph.go
• Topological Sort
  • https://github.com/theodesp/go-leetcode/blob/master/graphs/directedGraph.go
  • https://www.geeksforgeeks.org/topological-sorting/

TREES

• Invert a tree:
  • https://www.techiedelight.com/invert-binary-tree-recursive-iterative/
  • https://github.com/theodesp/go-leetcode/blob/master/trees/invertTree.go
• Tree traveral:
  • https://github.com/theodesp/go-leetcode/blob/master/trees/BinaryTree.go
  • https://www.geeksforgeeks.org/tree-traversals-inorder-preorder-and-postorder/
  • https://leetcode.com/problems/binary-tree-preorder-traversal/
  • https://leetcode.com/problems/binary-tree-postorder-traversal/
  • https://leetcode.com/problems/binary-tree-inorder-traversal/
  • https://leetcode.com/problems/binary-tree-level-order-traversal/
• Insert into BST:
  • https://github.com/theodesp/go-leetcode/blob/master/trees/BinarySearchTree.go
  • https://www.geeksforgeeks.org/binary-search-tree-set-1-search-and-insertion/
  • https://leetcode.com/problems/insert-into-a-binary-search-tree/
  • https://leetcode.com/problems/search-in-a-binary-search-tree/
• Delete in BST:
  • https://github.com/theodesp/go-leetcode/blob/master/trees/BinarySearchTree.go
  • https://www.geeksforgeeks.org/binary-search-tree-set-2-delete/
• Lowest common ancestor of BST
  • https://github.com/theodesp/go-leetcode/blob/master/trees/BinarySearchTree.go
  • https://www.geeksforgeeks.org/lowest-common-ancestor-binary-tree-set-1/
  • https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/
• Print Nodes at distance K from root of BST
  • https://leetcode.com/problems/all-nodes-distance-k-in-binary-tree/
  • https://www.dineshonjava.com/print-nodes-at-k-distance-from-the-root/
• Check if a binary tree is subtree of another binary tree:
  • https://github.com/theodesp/go-leetcode/blob/master/trees/subteeOfAnotherTree.go
  • https://leetcode.com/problems/subtree-of-another-tree/
  • https://www.geeksforgeeks.org/check-if-a-binary-tree-is-subtree-of-another-binary-tree/
• Check if two trees are mirror:
  • https://www.geeksforgeeks.org/check-if-two-trees-are-mirror/

SEARCHING

• Binary Search Impl:
  • https://www.geeksforgeeks.org/binary-search/
  • https://github.com/theodesp/go-leetcode/blob/master/binarySearch/binSearch.go
• Compute SQRT of integer:
  • https://www.geeksforgeeks.org/square-root-of-an-integer/
  • https://github.com/theodesp/go-leetcode/blob/master/binarySearch/sqrt.go
• Find starting and ending position of value in sorted array
  • https://medium.com/@saurav.agg19/find-first-and-last-position-of-element-in-sorted-array-82116ab6c187
  • https://github.com/theodesp/go-leetcode/blob/master/binarySearch/searchRange.go
• Implement indexOf string:
  • https://github.com/theodesp/go-leetcode/blob/master/uncategorized/KmpSearch.go
  • https://www.techiedelight.com/implement-strstr-function-java/
  • https://www.geeksforgeeks.org/kmp-algorithm-for-pattern-searching/
• Find Peak Element:
  • https://github.com/theodesp/go-leetcode/blob/master/binarySearch/findPeakElement.go
  • https://www.geeksforgeeks.org/find-a-peak-in-a-given-array/
• Find Peak Element in 2d array:
  • https://www.geeksforgeeks.org/find-peak-element-2d-array/
  • https://github.com/theodesp/go-leetcode/blob/master/binarySearch/findPeakElement2d.go
• Rabin-Karp efficient searching:
  • https://github.com/theodesp/go-leetcode/blob/master/searching/rabinCarpMatch.go
  • https://www.geeksforgeeks.org/rabin-karp-algorithm-for-pattern-searching/

SORTING

• Selection Sort:
  • https://github.com/theodesp/leetcode-scala/blob/master/Grokking/src/Ch2.scala
  • https://www.techiedelight.com/selection-sort-iterative-recursive/
• QuickSort:
  • https://github.com/theodesp/leetcode-scala/blob/master/Grokking/src/Ch4.scala
  • https://www.techiedelight.com/quicksort/
• SortBy:
  • https://github.com/theodesp/leetcode-scala/blob/master/Leetcode/src/QueueReconstuctionHeight.scala
• Counting Sort:
  • https://github.com/theodesp/go-leetcode/blob/master/sorting/countinSort.go
  • https://www.geeksforgeeks.org/counting-sort/
• Radix Sort:
  • https://www.geeksforgeeks.org/radix-sort/
  • https://github.com/theodesp/go-leetcode/blob/master/sorting/radixSort.go
• Merge Sort:
  • https://www.golangprograms.com/golang-program-for-implementation-of-mergesort.html
  • https://github.com/theodesp/go-leetcode/blob/master/sorting/mergeSort.go

ALGORITHMICS

• Add Two Binary Strings:
  • https://github.com/theodesp/go-leetcode/blob/master/uncategorized/AddBinary.go
  • https://www.geeksforgeeks.org/program-to-add-two-binary-strings/
• Check if string is palindrome:
  • https://github.com/theodesp/go-leetcode/blob/master/uncategorized/ValidPalindrome.go
  • https://www.techiedelight.com/determine-given-string-is-palindrome-not/
  • https://www.geeksforgeeks.org/c-program-check-given-string-palindrome/
• Click Counts
  • https://leetcode.com/problems/subdomain-visit-count/discuss/?currentPage=1&orderBy=hot&query=
  • https://github.com/theodesp/leetcode-scala/blob/master/Leetcode/src/CountClickCount.scala
• Longest Substring no-repeating chars
  • https://github.com/theodesp/leetcode-scala/blob/master/Leetcode/src/LongestSubstringNonRepeating.scala
  • https://www.techiedelight.com/find-longest-substring-given-string-containing-distinct-characters/
  • https://www.geeksforgeeks.org/length-of-the-longest-substring-without-repeating-characters/
• Check if string can be rearanged to form a Palindrome
  • https://www.geeksforgeeks.org/check-characters-given-string-can-rearranged-form-palindrome/
  • https://github.com/theodesp/go-leetcode/blob/master/uncategorized/checkCharsCanFormPalindrome.go

DFS

• Implementation:
  • https://github.com/theodesp/leetcode-scala/blob/master/Grokking/src/Ch6.scala
  • https://www.techiedelight.com/depth-first-search/

DYNAMIC PROGRAMMING

• Theory
  • https://www.geeksforgeeks.org/dynamic-programming/
• Longest Common Substring
  • https://github.com/theodesp/leetcode-scala/blob/master/Grokking/src/Ch7.scala
  • https://www.techiedelight.com/longest-common-substring-problem/
  • https://www.geeksforgeeks.org/longest-common-substring-dp-29/
• Knapsack
  • https://github.com/theodesp/go-leetcode/blob/master/dynamicProgramming/knapSack.go
  • https://www.geeksforgeeks.org/0-1-knapsack-problem-dp-10/
• SubArray Sum
  • https://www.geeksforgeeks.org/number-subarrays-sum-exactly-equal-k/
  • https://github.com/theodesp/go-leetcode/blob/master/uncategorized/SubArraySums.go

PRIME NUMBERS

• Find all prime numbers until n
  • https://gist.github.com/theodesp/305d2bea8f2a55bc6149a47bd5f2bcd8

STRINGS

• Find all substrings of given s
  • https://gist.github.com/theodesp/5bb4faa69c3a8f620adee359c770aed2
  • https://www.geeksforgeeks.org/program-print-substrings-given-string/

CACHING

• LFU Cache Implementation
  • https://github.com/theodesp/go-leetcode/blob/master/caching/LFUCache.go
• LRU Cache Implementation
  • https://github.com/theodesp/go-leetcode/blob/master/caching/LRUCache.go
  • https://leetcode.com/problems/lru-cache/
  • https://www.geeksforgeeks.org/lru-cache-implementation/