Data Structures & Algorithms Interview Questions

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

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

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

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

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

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

Alessandro R. - "import java.util.*; public class NetworkTopology { public int topologytype(int N, int M, int[] input3, int[] input4) { if (M != N - 1 && M != N) return -1; // Fast check for invalid cases int[] degree = new int[N + 1]; // Degree of each node (1-based indexing) // Build the degree array for (int i = 0; i < M; i++) { degree[input3[i]]++; degree[input4[i]]++; } // Check for Bus Topology boolean isBus = (M"See full answer

Sue G. - "Race Condition i,e multiple threads modifying simultaneously can lead to data inconsistency Operations like putIfAbsent() or computeIfAbsent() are not atomoic i.e duplicate entries or missing updates when multiple threads perform operations Data Corruption : during resizing of a hashmap by a thread, if another thread is accessing the same data , buckets can get corrupted, leading to a loss of data"See full answer

Sourav K. - "We can use a pool of memory where each index we can store the parent of current index then we can use same lca approach for array instead of pointers."See full answer

Anonymous Eel - "String commonStr(String str1, String str2) { int len1 = str1.length(); int len2 = str2.length(); if (len1 == 0 || len2 == 0) return ""; // let dpx reprsent the longest common str of 0...x int dp = new int len1 + 1; int maxLen = 0; int endIndex = 0; for (int i = 1; i <= len1; i++) { for (int j = 1; j <= len2; j++) { if (str1.charAt(i-1) == str2.charAt(j-1)) { dpi = dpi-1 + 1; "See full answer