Given two strings needle and haystack, return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Example 1: Input: haystack = ...

Given an integer array nums of length n and an integer target, find three integers in nums such that the sum is closest to target. Return the sum of ...

Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, and nums[i] ...

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display ...

Given two strings text1 and text2, return the length of their longest common subsequence. If there is no common subsequence, return 0. A subsequence of a string is a new ...

A linked list of length n is given such that each node contains an additional random pointer, which could point to any ...

Implement pow(x, n), which calculates x raised to the power n (i.e., xn). Example 1: Input: x = 2.00000, n = 10 Output: 1024.00000 Example 2: ...

Write a function to find the longest common prefix string amongst an array of strings. If there is no common ...

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol                Value I 1 V ...

Given n non-negative integers a1, a2, ..., an , where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two ...