Suppose we have a binary tree; we have to check whether all leaves are at the same level or not.So, if the input is likethen the output will be TrueTo solve this, we will follow these steps −Define a function dfs() . This will take root, dif root is not null, thenif left of root is null and right of root is null, theninsert d at the end of depthotherwise, dfs(left of root, d + 1)dfs(right of root, d + 1)From the main method, do the following −depth := a new listdfs(root, 0)return true when depth has only one valueLet ... Read More

Suppose we have one n × n matrix containing values from 0 to n. Here 0 represents an unfilled square, we have to check whether we can fill empty squares such that in each row and each column every number from 1 to n appears exactly once.So, if the input is like002201123then the output will be True, as we can set the matrix to312231123To solve this, we will follow these steps −Define a function find_empty_cell() . This will take matrix, nfor i in range 0 to n, dofor j in range 0 to n, doif matrix[i, j] is same as ... Read More

Suppose we have a binary tree; we have to find the maximum sum of any path between any two nodes.So, if the input is likethen the output will be 62 as the nodes are [12, 13, 14, 16, 7].To solve this, we will follow these steps −Define a function utils() . This will take rootif root null, thenreturn 0l := utils(left of root)r := utils(right of root)max_single := maximum of (max of l and r) + value of root) and value of rootmax_top := maximum of max_single and l + r + value of rootres := maximum of res and ... Read More

Suppose we have a list of numbers called nums, we will define a function that returns the largest sum of non-adjacent numbers. Here the numbers can be 0 or negative.So, if the input is like [3, 5, 7, 3, 6], then the output will be 16, as we can take 3, 7, and 6 to get 16.To solve this, we will follow these steps−if size of nums

Suppose we have an array A. We have to find the contiguous sublist which has the maximum sum, and also return its sum. So if the array A is like A = [-2, 1, -3, 4, -1, 2, 1, -5, 4], then the sum will be 6. And the subarray will be [4, -1, 2, 1].To solve this we will try to use Dynamic programming approach.define an array dp same as the size of A, and fill it with 0dp[0] := A[0]for i := 1 to size of A – 1dp[i] := maximum of dp[i – 1] + A[i] and ... Read More

Suppose we have a list of numbers nums, now consider a circular list of nums where the start and end of nums are neighbors. We have to find the maximum sum of a non-empty sublist in the circular list.So, if the input is like nums = [2, 3, -7, 4, 5], then the output will be 14, as we can take the sub list [4, 5, 2, 3] which sums to 14.To solve this, we will follow these steps −max_sum := negative infinity, cur_max := 0min_sum := positive infinity, cur_min := 0for each num in nums, docur_max := maximum of ... Read More

Suppose we have a list of numbers called nums and an integer k, we have to select elements from nums to create a list of size k such that the difference between the largest integer in the list and the smallest integer is as low as possible. And we will return this difference.So, if the input is like nums = [3, 11, 6, 2, 9], k = 3, then the output will be 4, as the best list we can make is [2, 3, 6].To solve this, we will follow these steps −sort the list numsls := a new listfor ... Read More

Suppose we have a list of strings words, we have to group all anagrams together and return the size of the largest grouping.So, if the input is like words = ["xy", "yx", "xyz", "zyx", "yzx", "wwwww"], then the output will be 3, as ["xyz", "zyx", "yzx"] is the largest grouping.To solve this, we will follow these steps −lookup := a new map, initially emptyres := 0for each i in words, dop := sort i in lexicographical wayif p is in lookup, increase count, otherwise 1res := maximum of res and lookup[p]return resLet us see the following implementation to get better ... Read More

Suppose we have a string s of lowercase alphabet characters, and another number k, we have to find the minimum number of required changes in the string so that the resulting string has at most k distinct characters. In this case The change is actually changing a single character to any other character.So, if the input is like s = "wxxyyzzxx", k = 3, then the output will be 1, as we can remove the letter "w" to get 3 distinct characters (x, y, and z).To solve this, we will follow these steps −count := a map of each character ... Read More

Suppose we have a list of sorted unique numbers called nums and an integer k, we have to find the kth missing number from the first element of the given list.So, if the input is like nums = [5, 6, 8, 10, 11], k = 1, then the output will be 9, as 9 is the second (index 1) missing number.To solve this, we will follow these steps −for i in range 1 to size of nums, dodiff := nums[i] - nums[i - 1] - 1if k >= diff, thenk := k - diffotherwise, return nums[i - 1] + k ... Read More