There are 8 prison cells in a row, and each cell is either occupied or vacant. Each day, whether the cell is occupied or vacant changes according to the following rules: If a cell has two adjacent neighbors that are both occupied or both vacant, then the cell becomes occupied. Otherwise, it becomes vacant. (Note that because the prison is a row, the first and the last cells in the row can’t have two adjacent neighbors.
Given a paragraph and a list of banned words, return the most frequent word that is not in the list of banned words. It is guaranteed there is at least one word that isn’t banned, and that the answer is unique. Words in the list of banned words are given in lowercase, and free of punctuation. Words in the paragraph are not case sensitive. The answer is in lowercase. Example: Input: paragraph = "Bob hit a ball, the hit BALL flew far after it was hit.
Tree: n - 1 edges, all nodes connected, contains no loop.
Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected graph. Example 1 Input: n = 5 and edges = [[0, 1], [1, 2], [3, 4]] 0 3 | | 1 --- 2 4 Output: 2 Example 2 Input: n = 5 and edges = [[0, 1], [1, 2], [2, 3], [3, 4]] 0 4 | | 1 --- 2 --- 3 Output: 1 Note You can assume that no duplicate edges will appear in edges.
Given n nodes labeled from 0 to n-1 and a list of undirected edges (each edge is a pair of nodes), write a function to check whether these edges make up a valid tree. ###Example 1: Input: n = 5, and edges = [[0,1], [0,2], [0,3], [1,4]] Output: true Example 2 Input: n = 5, and edges = [[0,1], [1,2], [2,3], [1,3], [1,4]] Output: false ###Note: you can assume that no duplicate edges will appear in edges.
We have a list of points on the plane. Find the K closest points to the origin (0, 0). (Here, the distance between two points on a plane is the Euclidean distance.) You may return the answer in any order. The answer is guaranteed to be unique (except for the order that it is in.) Example 1 Input: points = [[1,3],[-2,2]], K = 1 Output: [[-2,2]] Explanation: The distance between (1, 3) and the origin is sqrt(10).
Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), determine if a person could attend all meetings. Example 1 Input: [[0,30],[5,10],[15,20]] Output: false Example 2 Input: [[7,10],[2,4]] Output: true Solution /** * Definition for an interval. * public class Interval { * int start; * int end; * Interval() { start = 0; end = 0; } * Interval(int s, int e) { start = s; end = e; } * } */ class Solution { public boolean canAttendMeetings(Interval[] intervals) { Arrays.
A robot is located at the top-left corner of a m x n grid (marked ‘Start’ in the diagram below). The robot can only move either down or right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked ‘Finish’ in the diagram below). Now consider if some obstacles are added to the grids. How many unique paths would there be? An obstacle and empty space is marked as 1 and 0 respectively in the grid.
There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next station (i+1). You begin the journey with an empty tank at one of the gas stations. Return the starting gas station’s index if you can travel around the circuit once in the clockwise direction, otherwise return -1.
Given n non-negative integers representing the histogram’s bar height where the width of each bar is 1, find the area of largest rectangle in the histogram. Above is a histogram where width of each bar is 1, given height = [2,1,5,6,2,3]. The largest rectangle is shown in the shaded area, which has area = 10 unit. Example: Input: [2,1,5,6,2,3] Output: 10 Solution: Push height into the stack in ascending order. When we encounter a height that is shorter than te top of the stack, we start to calculate area by popping heights out of the stack.