Problems

29 problems

• Easy

  Two Sum

  Given an array of integers nums and an integer target, return indices …

  Arrays Hashing
• Easy

  Best Time to Buy and Sell Stock

  You are given an array prices where prices[i] is the price of …

  Arrays Dynamic Programming
• Easy

  Contains Duplicate

  Given an integer array nums, return true if any value appears at …

  Arrays Hashing
• Easy

  Move Zeroes

  Given an integer array nums, move all 0's to the end of …

  Arrays Two Pointers
• Easy

  Plus One

  Given digits representing a non-negative integer, return the integer plus one.

  Arrays Math
• Easy

  Missing Number

  Given distinct numbers in [0, n], return the missing number.

  Arrays Math
• Easy

  Valid Mountain Array

  Return true if arr strictly increases then strictly decreases.

  Arrays Two Pointers
• Easy

  Squares of a Sorted Array

  Return sorted squares of each number.

  Arrays Two Pointers
• Easy

  Running Sum of 1D Array

  Return running sum of nums.

  Arrays Prefix Sum
• Easy

  Richest Customer Wealth

  Return max row sum in accounts matrix.

  Arrays Matrix
• Easy

  Pascal's Triangle II

  Return the rowIndex-th row of Pascal's triangle.

  Arrays Dynamic Programming
• Easy

  Find Pivot Index

  Return index where left sum equals right sum, else -1.

  Arrays Prefix Sum
• Easy

  Intersection of Two Arrays

  Return unique intersection in sorted order.

  Arrays Hashing
• Easy

  Majority Element

  Return the element that appears more than n/2 times.

  Arrays Greedy
• Easy

  Monotonic Array

  Return true if array is monotone increasing or decreasing.

  Arrays
• Easy

  Reshape the Matrix

  Reshape matrix to r x c if possible, else return original.

  Arrays Matrix
• Easy

  Kth Missing Positive Number

  Return the k-th missing positive integer.

  Arrays Binary Search
• Easy

  Intersection of Two Arrays II

  Return intersection with multiplicity in sorted order.

  Arrays Hashing
• Medium

  Kth Largest Element in an Array

  Given an integer array nums and an integer k, return the k-th …

  Arrays Divide and Conquer Sorting
• Medium

  Top K Frequent Elements

  Return top k frequent numbers sorted ascending by value in ties.

  Arrays Hashing Heap
• Medium

  Subarray Sum Equals K

  Count contiguous subarrays that sum to k.

  Arrays Hashing Prefix Sum
• Medium

  Search in Rotated Sorted Array

  Return index of target in rotated sorted array, else -1.

  Arrays Binary Search
• Medium

  Find Minimum in Rotated Sorted Array

  Return minimum element in rotated sorted array.

  Arrays Binary Search
• Medium

  Longest Consecutive Sequence

  Return length of the longest consecutive elements sequence.

  Arrays Hashing
• Medium

  Gas Station

  Return starting station index to complete circuit, else -1.

  Arrays Greedy
• Medium

  Insert Interval

  Insert a new interval and merge if necessary.

  Arrays Intervals
• Medium

  Find K Closest Elements

  Return k closest elements to x in ascending order.

  Arrays Binary Search Two Pointers
• Hard

  Median of Two Sorted Arrays

  Return median of two sorted arrays.

  Arrays Binary Search
• Hard

  Sliding Window Maximum

  Return max value in each sliding window of size k.

  Arrays Deque Sliding Window