Data Structures & Algorithms Interview Questions

Konstantin P. - "Count how many 1 and 2. calculate how many remaining items with '0'. Override existing data with knowledge of how many '0','1','2' in that order; TC=O(n), SC=O(1)"See full answer

Shar N. - "standard answer for this."See full answer

Susmita S. - "Function that transforms each elements in a collection and returns new collection with transformed elements"See full answer

Yash S. - "Run length encoding. This will preserve order of values in vector."See full answer

Aniket G. - "public class BoggleBoard { public static List findWords(char board, Set dictionary) { int rows = board.length; int cols = board[0].length; boolean visited = new booleanrows; int directions = {{1,0}, {-1,0}, {0,1}, {0,-1}}; List result = new ArrayList(); for(int i=0; i<rows; i++) { for(int j=0; j<cols; j++) { dfs(board, visited, i, j, dictionary, "", result, dire"See full answer

Tushar A. - "class Node { int val; Node left, right; Node(int v) { val = v; left = right = null; } } class BinaryTree { Node root1, root2; boolean identicalTrees(Node a, Node b) { if (a == null && b == null) return true; if (a != null && b != null) return (a.val == b.val && identicalTrees(a.left, b.left) && identicalTrees(a.right, b.right)); "See full answer

Mohith J. - "Recursion: 0 if NULL, else 1+max(height(left), height(right))"See full answer

Ugo C. - "function constructTree(n, matrix) { let parent = []; let child = []; let root = null; for (let i = 0; i < n; i++) { for (let j = 0; j < n; j++) { if (matrixi === 1) { parent.push(i); child.push(j); } } } for (let i = 0; i < n; i++) { if (parent.indexOf(i) === -1) { root = i; } } let node = new Node(root); for (let i = 0; i < n; i++) { if (i !== root) { constructTreeUtil(node, parent[i], child[i]); } } return node; }"See full answer

Anonymous Emu - "let str = 'this is a test of programs'; let obj={}; for (let s of str ) obj[s]?(obj[s]=obj[s]+1):(obj[s]=1) console.log(JSON.stringify(obj))"See full answer

Weida H. - "filter function usually exists in some high level programming that adopt FP paradigm. It taks a sequence of items and a predicate function, and returns (conceptually) a subset of the items that satisfy the predicate. Adopt this kind of operation (filter, map, reduce, take, pairwise ...) can help writting cleaner code, and reduce the usage of mutable part in the program, lower the possibility of making human mistake. Take Python for example (although const-ness is not exists in Python), assu"See full answer

Rudransh V. - "I got it right"See full answer

Yitayal B. - "import re def naturalsortkey(s): Split the string into a list of text and numbers "item10" -> ["item", 10] return [int(text) if text.isdigit() else text.lower() for text in re.split(r'(\d+)', s)] def natural_sort(arr): return sorted(arr, key=naturalsortkey) \# Example Usage data = ["item10", "item2", "item1", "item20", "2nd item", "1st item"] sorteddata = naturalsort(data) print(f"Standard Sort: {sorted(data)}") print(f"Natural Sort: {sorted_data}") "See full answer