Array

LeetCode problem #134

Given a sorted array of integers and a target value, return the index of the target if found, or -1 if not present.

Determine if an array is sorted in ascending, descending, or not sorted at all

Convert a sorted array to a height-balanced binary search tree.

Find the number of days until a warmer temperature for each day.

Design a circular queue with fixed size that supports enqueue, dequeue, front, rear, isEmpty, and isFull operations.

Find the duplicate number in an array containing n+1 integers where each integer is between 1 and n (inclusive)

Find and return the largest element in an array of integers

Find and return the second largest element in an array of integers

Implement a queue using arrays or linked lists with O(1) time complexity for all operations.

Design and implement a stack data structure with push, pop, top, and empty operations

Maximize array sum by flipping signs of k elements using greedy heap approach

Given two sorted arrays nums1 and nums2, return the median of the two sorted arrays. The overall run time complexity should be O(log(min(m,n))).

Given an array of intervals where intervals[i] = [start_i, end_i], merge all overlapping intervals and return an array of the non-overlapping intervals that cover all the intervals in the input.

LeetCode 88 merge sorted array in-place: reverse two pointers (merge from end) in O(m+n) time, O(1) space. Step-by-step + examples.

Find the missing number in an array containing n distinct numbers taken from 0, 1, 2, ..., n.

Move all zeros in an array to the end while maintaining the relative order of non-zero elements

Find the next greater element for each element in an array.

Find minimum removals to reduce array size by half using greedy heap approach

Reverse the order of elements in an array in-place and return the modified array

Rotate an array to the right by k steps where k is non-negative

Given a rotated sorted array and a target value, return the index of the target if found in O(log n) time, or -1 if not present.

Find the maximum element in each sliding window of size k

Calculate the span of stock prices for each day

Find a subarray with a given sum in an array of positive integers.

Calculate how much rainwater can be trapped between bars of different heights

Find two numbers in an array that add up to a target value.

Given an array of integers and a target, return indices of two numbers that add up to the target.