Anagram Substrings
Given two strings s0 and s1, return the number of substrings where s1 contains any anagram of s0.
Posts with tag 'hash table'
Remove Duplicate Numbers
Given a list of integers nums, remove numbers that appear multiple times in the list, while maintaining order of the appearance in the original list.
Frequency Stack
Implement a frequency stack with the following methods:
Longest Consecutive Sequence
Given an unsorted array of integers nums, find the length of the longest sequence of consecutive elements.
Longest Substring with 2 Distinct Characters
Given a string s, find the length of the longest substring that contains at most 2 distinct characters.
Sum of Four Numbers
Given a list of integers nums and an integer k, return whether there are four distinct elements in the list that add up to k.
Sum Pairs to Target
You are given a list of integers nums and an integer target. In one operation we can remove any two numbers in nums if the pair sums to target. Return the ma...
Characters in Each Bracket Depth
You are a given a string s containing "X", "(", and ")". The string has balanced brackets and in between there are some "X"s along with possibly nested brack...
Earliest Uniques in a Stream
Implement a data structure with the following methods:
Sort by Frequency and Value
Given a list of integers nums, order nums by frequency, with most frequent values coming first. If there’s a tie in frequency, higher valued numbers should c...
Condo Developers
You are given a two-dimensional integer matrix, where matrix[r][c] represents the height of a condominium in a city.
Bomber Man
You are given a two-dimensional integer matrix of 1s and 0s, where a 1 represents a bomb and 0 represents an empty cell. When a bomb explodes, all the spaces...
Underground Tunnel
Implement a data structure with the following methods:
Largest Anagram Group
Given a list of strings words, group all anagrams together and return the size of the largest grouping.
K Unique String
Given a string s of lowercase alphabet characters, and an integer k, return the minimum number of changes needed in the string (one change involves changing ...
Count of Sublists with Same First and Last Values
Given a list of integers nums, return the number of sublists where the first element and the last element have the same value.
Palindromic Anagram
Given a string s, determine whether any anagram of s is a palindrome.
Anagram Checks
Given two strings s0 and s1, return whether they are anagrams of each other.
Zero Matrix
Given a two-dimensional matrix of integers, for each zero in the original matrix, replace all values in its row and column with zero, and return the resultin...
Word Formation
Given a list of strings words and a string letters, return the length of longest string in words that can be made from letters in letters. If no word can be ...
Virtual Boolean Array
Implement a boolean array which implements the following methods:
Unique People in Contact List
You are given a two-dimensional list of strings contacts. Each element contacts[i] represents the list of emails for contact i. Contact i is considered a dup...
Unique Occurrences
Given a list of integers nums, return whether the number of occurrences of every value in the array is unique.
Tic Tac Toe
Implement the tic-tac-toe game with the following methods:
Swap Characters to Equalize Strings
You are given two lowercase alphabet strings s and t, both of them the same length. You can pick one character in s and another in t and swap them. Given you...
Sum of Two Numbers
Given a list of numbers nums and a number k, return whether any two elements from the list add up to k. You may not use the same element twice.
Sum of Three Numbers
Given a list of integers nums and an integer k, determine if there are three distinct elements in the list that add up to k.
String Isomorphism
Given lowercase alphabet strings s, and t return whether you can create a 1-to-1 mapping for each letter in s to another letter (could be the same letter) su...
Shortest Sublist With Max Frequency
You are given a list of integers nums. Let k be the frequency of a most frequent number in nums. Return the length of a shortest sublist such that the freque...
Selling Products
You are given a list of integers items and an integer n. A salesperson has items in a bag with random IDs. The salesperson can remove as many as n items from...
Remove Last Duplicate Entries
Given a list of integers nums, find all duplicate numbers and delete their last occurrences.
Number of Sublists With Sum of Target
Given a list of integers nums and an integer target, return the number of sublists whose sum is equal to target.
Mutual Followers
You are given a two-dimensional list of integers relations. Each element relations[i] contains [a, b] meaning that person a is following person b on Twitter.
Minimum String
You are given two strings s and t of equal length only consisting of lowercase letters. Assuming that you can first rearrange s into any order, return the mi...
Minimize Number of Unique Integers After Removals
You are given a list of integers nums and an integer n. Given you must remove exactly n numbers, return the least number of unique integers after the removal...
List Partitioning
Given a list of strings strs, containing the strings "red", "green" and "blue", partition the list so that the red come before green, which come before blue.
Leaderboard
You are given a list of integers nums, representing the number of chess matches each person has won. Return a relative ranking (0-indexed) of each person. If...
Latin Square
Given an n by n matrix of letters matrix, return whether there are exactly n different letters that appear in the matrix and each letter appears exactly once...
K and -K
Given a list of integers nums, return the largest integer k where k and -k both exist in nums (they can be the same integer). If there’s no such integer, ret...
High Frequency
Given a list of integers nums, find the most frequently occurring element and return the number of occurrences of that element.
Hash Table
Implement a hash table with the following methods:
First Missing Positive
Given a list of integers nums, find the first missing positive integer. In other words, find the lowest positive integer that does not exist in the list. The...
File System
Implement a data structure with the following methods:
Equivalent Value and Frequency
Given a list of integers nums, return whether there’s an integer whose frequency in the list is same as its value.
Equivalent Pairs
You are given a list of integers nums. Return the number of pairs i < j such that nums[i] = nums[j].
Detect Voter Fraud
Given a two dimensional list of integers votes, where each list has two elements [candidate_id, voter_id], report whether any voter has voted more than once.
Common Words
Given two strings s0 and s1, each representing a sentence, return the number of unique words that are shared between the two sentences.
City Blocks
You are given a two-dimensional matrix of unique strings representing city blocks, and a list of strings blocks to visit. Given that you are sitting at block...
A Unique String
Given a lowercase alphabet string s, determine whether it has all unique characters.
A Number and Its Triple
Given a list of integers nums, return whether there’s two numbers such that one is a triple of another.