Suppose we have a 2D binary matrix where 1 represents a communication tower, and 0 represents an empty cell. The towers can communicate in the following ways: 1. If tower A, and tower B are either on the same row or column, they can communicate with each other. 2. If tower A can talk with tower B and B can talk with C, then A can talk to C (transitive property). We have to find the total number of tower groups there are (here a group is a list of towers that can talk with each other).So, if the input ... Read More

Suppose we have two values hours and minutes. We have to find a smaller angle formed between the hour and the minute hand.So, if the input is like hour = 12 minutes = 45, then the output will be 112.5To solve this, we will follow these steps:if h = 12, then set h := 0if m = 60, then set m := 0hAngle := 0.5 * (60h) + mmAngle := 6mret := |hAngle - mAngle|return minimum of ret and (360 – ret)Let us see the following implementation to get better understanding:Example Live Demo#include using namespace std; class Solution { public: ... Read More

Suppose we have a list of intervals in the form [start, end], this is representing the start and end time of a course. We have to find the maximum number of courses we can take, assuming we can only take one course at a time and the start of a course needs to be later than the end of the last course.So, if the input is like times = [[3, 6], [6, 9], [7, 8], [9, 11]], then the output will be 3, as we can take courses [[3, 6], [7, 8], [9, 11]]To solve this, we will follow these ... Read More

Suppose we have a list of boxes, here each entry has two values [start, end] (start < end). We can join two boxes if the end of one is equal to the start of another. We have to find the length of the longest chain of boxes.So, if the input is like blocks = [ [4, 5], [5, 6], [4, 8], [1, 2], [2, 4] ], then the output will be 4, as we can form the chain: [1, 2], [2, 4], [4, 5], [5, 6]To solve this, we will follow these steps:if boxes are empty, thenreturn 0sort the list ... Read More

Suppose we have a list of numbers called candies and someone is playing a game against his/her friend. In each round, a player can remove any two consecutive candies with the same value. And whoever can not pick up a candy loses and that player1 start first, we have to check whether player1 will win or not.So, if the input is like nums = [2, 2, 5], then the output will be True, as if player1 picks the 2s then the other player cannot pick any candies.To solve this, we will follow these steps:stack := a new stackturns := 0for ... Read More

Suppose we have a string s containing a boolean expression with operators "and" and "or", evaluate it and return the result. Here the expressions may have parentheses, which should be evaluated first.So, if the input is like s = "T and (F or T)", then the output will be TrueTo solve this, we will follow these steps:stack := a new listt = list of elements of s split by blank spacesfor each v in t, doif v[0] is same as "(", thenpush true when v[from index of "(" to end] is same as "T", into stackotherwise when ")" is found, ... Read More

Suppose we have a list of sorted numbers called days, where we must take the bus for on each day. We have to find the lowest cost it takes to travel for all the days. There are 3 types of bus tickets. 1-day pass for 2 bucks 7-day pass for 7 bucks 30-day pass for 25 bucksSo, if the input is like days = [1, 3, 5, 6, 28], then the output will be 9, as the lowest cost can be achieved by purchasing a 7-day pass in the beginning and then a 1-day pass on the 29th day.To solve ... Read More

Suppose we have two lists of numbers L1 and L2, the length of each list is n and each value is unique to its list, and values are in range 1 to n, we have to find the minimum number of adjacent swaps required to transform L1 to L2.So, if the input is like L1 = [0, 1, 2, 3] L2 = [2, 0, 1, 3], then the output will be 2, as we can swap 1 and 2, L1 will be [0, 2, 1, 3], and then 0 and 2, L1 will be [2, 0, 1, 3], this is ... Read More

Suppose we have a list of stock prices of a company in chronological sequence, and also have the transaction fee for one sell transaction. We have to find the maximum profit we could have made from buying and selling that stock any number of times. We must buy before we can sell it.So, if the input is like prices = [2, 10, 4, 8] fee = 3, then the output will be 6, as we can buy at 2 and sell at 10 and incur a fee of 3, so profit is 5. Then we buy at 4 and sell ... Read More

Suppose we have a 2D matrix of three different values, 2s, 1s, and 0s, where a 2 represents an enemy, 1 represents a wall and 0 represents an empty cell. We have to find the maximum enemies we can kill using one bomb. The bomb kills all the enemies in the same row and column from the planted point until it hits the wall. And we can put bombs only on blank spaces.So, if the input is likethen the output will be 3, as we can place the bomb at the green box to kill maximum 3 enemies.ret := 0n ... Read More