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Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.
Find two numbers that add up to target in a sorted array using constant extra space O(1).
Given an array of integers temperatures, return an array answer such that answer[i] is the number of days you have to wait for a warmer temperature.
Given an array of integers nums sorted in ascending order, search target in O(log n) runtime.
Find a contiguous subarray whose length is equal to k that has the maximum average value in O(N) linear time.
Given head, the head of a linked list, determine if the linked list has a cycle in it using Floyd's Tortoise and Hare.
Given the root of a binary tree, invert the tree, and return its root.
Implement a trie with insert, search, and startsWith methods.
Design a class to find the kth largest element in a stream.
Given an integer array nums of unique elements, return all possible subsets (the power set).
Given an array of intervals, merge all overlapping intervals.
Find the subarray with the largest sum, and return its sum.
Given an m x n 2D binary grid grid which represents a map of '1's (land) and '0's (water), return the number of islands.
You are climbing a staircase. It takes n steps to reach the top. Each time you can climb 1 or 2 steps. How many distinct ways?
Calculate minimum time for all nodes to receive a signal using Dijkstra's Algorithm.
A robot is located at the top-left corner of a m x n grid. How many possible unique paths to reach bottom-right?
Given a non-empty array of integers nums, every element appears twice except for one. Find that single one.
You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise) in-place.