1869. Longer Contiguous Segments of Ones than Zeros
Given a binary string s, return true if the longest contiguous segment of 1s is strictly longer than the longest contiguous segment of 0s in s. Return false otherwise.
- For example, in s = “110100010” the longest contiguous segment of 1s has length 2, and the longest contiguous segment of 0s has length 3.
Note that if there are no 0s, then the longest contiguous segment of 0s is considered to have length 0. The same applies if there are no 1s.
1870. Minimum Speed to Arrive on Time
You are given a floating-point number hour, representing the amount of time you have to reach the office. To commute to the office, you must take n trains in sequential order. You are also given an integer array dist of length n, where dist[i] describes the distance (in kilometers) of the ith train ride.
Each train can only depart at an integer hour, so you may need to wait in between each train ride.
- For example, if the 1st train ride takes 1.5 hours, you must wait for an additional 0.5 hours before you can depart on the 2nd train ride at the 2 hour mark.
Return the minimum positive integer speed (in kilometers per hour) that all the trains must travel at for you to reach the office on time, or -1 if it is impossible to be on time.
Tests are generated such that the answer will not exceed 107 and hour will have at most two digits after the decimal point.
You are given a 0-indexed binary string s and two integers minJump and maxJump. In the beginning, you are standing at index 0, which is equal to ‘0’. You can move from index i to index j if the following conditions are fulfilled:
- i + minJump <= j <= min(i + maxJump, s.length - 1), and
- s[j] == ‘0’.
Return true if you can reach index s.length - 1 in s, or false otherwise.
Alice and Bob take turns playing a game, with Alice starting first.
There are n stones arranged in a row. On each player’s turn, while the number of stones is more than one, they will do the following:
- Choose an integer x > 1, and remove the leftmost x stones from the row.
- Add the sum of the removed stones’ values to the player’s score.
- Place a new stone, whose value is equal to that sum, on the left side of the row.
The game stops when only one stone is left in the row.
The score difference between Alice and Bob is (Alice’s score - Bob’s score). Alice’s goal is to maximize the score difference, and Bob’s goal is the minimize the score difference.
Given an integer array stones of length n where stones[i] represents the value of the ith stone from the left, return the score difference between Alice and Bob if they both play optimally.
105. Construct Binary Tree from Preorder and Inorder Traversal
Given two integer arrays preorder and inorder where preorder is the preorder traversal of a binary tree and inorder is the inorder traversal of the same tree, construct and return the binary tree.
Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any order.
863. All Nodes Distance K in Binary Tree
We are given a binary tree (with root node root), a target node, and an integer value k.
Return a list of the values of all nodes that have a distance k from the target node. The answer can be returned in any order.
You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise).
You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation.
1570. Dot Product of Two Sparse Vectors
Given two sparse vectors, compute their dot product.
Implement class SparseVector:
- SparseVector(nums) Initializes the object with the vector nums
- dotProduct(vec) Compute the dot product between the instance of SparseVector and vec
A sparse vector is a vector that has mostly zero values, you should store the sparse vector efficiently and compute the dot product between two SparseVector.
Follow up: What if only one of the vectors is sparse?