Google Topics for Interview Preparation



Easy Level Medium Level Hard Level

Easy Level



  • Find all triplets with zero sum

  • Generate all binary strings from given pattern

  • Count of strings that can be formed using a, b and c under given constraints

  • Find largest word in dictionary by deleting some characters of given string

  • Find subarray with given sum | Set 1 (Nonnegative Numbers)

  • Find the longest substring with k unique characters in a given string

  • Find the two non-repeating elements in an array of repeating elements

  • Flood fill Algorithm - how to implement fill() in paint?

  • Meta Strings (Check if two strings can become same after a swap in one string)

  • Print all Jumping Numbers smaller than or equal to a given value

  • Sum of all the numbers that are formed from root to leaf paths

  • The Celebrity Problem

  • Unbounded Knapsack (Repetition of items allowed)



  • Medium Level



  • Backtracking | Set 7 (Sudoku)

  • Boggle | Set 2 (Using Trie)

  • Check if a Binary Tree contains duplicate subtrees of size 2 or more

  • Dynamic Programming | Set 33 (Find if a string is interleaved of two other stri

  • Connect nodes at same level

  • Count BST nodes that lie in a given range

  • Dynamic Programming | Set 11 (Egg Dropping Puzzle)

  • Dynamic Programming | Set 28 (Minimum insertions to form a palindrome)

  • Dynamic Programming | Set 31 (Optimal Strategy for a Game)

  • Dynamic Programming | Set 32 (Word Break Problem)

  • Find four elements that sum to a given value | Set 2 ( O(n^2Logn) Solution)

  • Given a matrix of ‘O’ and ‘X’, replace 'O' with 'X' if surrounded by 'X'

  • How to print maximum number of A's using given four keys

  • Inplace rotate square matrix by 90 degrees | Set 1

  • Maximum absolute difference between sum of two contiguous sub-arrays

  • Merge two BSTs with limited extra space

  • Merge Overlapping Intervals

  • Modular Exponentiation (Power in Modular Arithmetic)

  • Paper Cut into Minimum Number of Squares | Set 2

  • Sum of bit differences among all pairs



  • Hard Level



  • Allocate minimum number of pages

  • Given an array arr[], find the maximum j - i such that arr[j] > arr[i]

  • Given a sorted dictionary of an alien language, find order of characters

  • Hungarian Algorithm for Assignment Problem | Set 1 (Introduction)

  • Implement LRU Cache

  • Length of the longest valid substring

  • Median in a stream of integers (running integers)

  • Sum of bit differences among all pairs

  • Travelling Salesman Problem | Set 1 (Naive and Dynamic Programming)

  • Word Break Problem using Backtracking









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