We have a wooden plank of the length n units. Some ants are walking on the plank, each ant moves with speed 1 unit per second. Some of the ants move to the left, the other move to the right. When two

Design an algorithm to encode a list of strings to a string. The encoded string is then sent over the network and is decoded back to the original list of strings. Machine 1 (sender) has the function:

The count-and-say sequence is a sequence of digit strings defined by the recursive formula:countAndSay(1) = “1”countAndSay(n) is the way you would “say” the digit string from countAndSay(n-1), wh

Given an integer n, return the least number of perfect square numbers that sum to n. A perfect square is an integer that is the square of an integer; in other words, it is the product of some integer

Given two strings s and t, return true if s is a subsequence of t, or false otherwise. A subsequence of a string is a new string that is formed from the original string by deleting some (can be none)

Given an array of n integers nums and an integer target, find the number of index triplets i, j, k with 0 <= i < j < k < n that satisfy the condition nums[i] + nums[j] + nums[k] <

Given a m * n matrix of ones and zeros, return how many square submatrices have all ones. Example 1:Input: matrix =[ [0,1,1,1], [1,1,1,1], [0,1,1,1]]Output: 15Explanation:There are 10 squares

Design an algorithm that collects daily price quotes for some stock and returns the span of that stock’s price for the current day. The span of the stock’s price in one day is the maximum number of co

Given the string s, return the size of the longest substring containing each vowel an even number of times. That is, ‘a’, ‘e’, ‘i’, ‘o’, and ‘u’ must appear an even number of times. Example 1:Input: s

Given two strings s1 and s2, return true if s2 contains a permutation of s1, or false otherwise. In other words, return true if one of s1’s permutations is the substring of s2. Example 1:Input: s1 &#x