Suppose we have a 2D matrix represents a forest where there are three types of cells: 0 empty cell 1 tree cell 2 tree on fire cell Every day, a tree catches fire when there is an adjacent (top, down, left, right, not diagonal) tree is on fire. We have ... Read More

Suppose we have a binary tree and another value k, we have to find the number of unique node to sub child paths are there which sums to k.So, if the input is likeand k = 5, then the output will be 2, as the paths are [2, 3] and ... Read More

Suppose we have a binary tree where the value of each node represents its color. There are at most 2 colors in a tree. We have to check whether it is possible to swap the colors of the nodes any number of times so that no two connected nodes have ... Read More

Suppose we have a list of strings called votes, here each entry is in lowercase letters and they are representing votes on candidates in order from highest to lowest preference. Here the rank of a candidate depends first by the number of votes received on the highest preference. Now if ... Read More

Suppose we have a number n, and there are n switches in a room, and all switches are off. Now n people who flip switches as follows −Person 1 flips all switches that are multiples of 1 (so all of the switches).Person 2 flips switches that are multiples of 2 ... Read More

Suppose we have a binary matrix. Where 1 represents land and 0 represents water. As we know an island is a group of 1s that are grouped together whose perimeter is surrounded by water. We have to find the number of completely surrounded islands.So, if the input is likethen the ... Read More

Suppose we have a binary tree where each node is containing a single digit from 0 to 9. Now each path from the root to the leaf represents a number with its digits in order. We have to find the sum of numbers represented by all paths in the tree.So, ... Read More

Suppose we have a list of words and a string s, we have to find the number of strings in the words list that are subsequences of s.So, if the input is like words = ["xz", "xw", "y"] s = "xyz", then the output will be 2, as "xz" and ... Read More

Suppose we have two strings source and target, we have to find the minimum number of subsequences of source we can form such that if we concatenate them, it will be same as target. If there is no such result, return -1.So, if the input is like source = "xyz" ... Read More

Suppose we have a list of numbers called nums where each number represents a vote to a candidate. We have to find the ids of the candidates that have greater than floor(n/3) votes, in non-decreasing order.So, if the input is like nums = [3, 2, 6, 6, 6, 6, 7, ... Read More