Suppose we have a non-empty string; we have to encode this string such that its encoded length will be minimum.The encoding rule is like − k[encoded_string], where the encoded_string inside [ ] is being repeated exactly k times. We have to keep in mind that k will be a positive integer and encoded string will not be empty or have extra space. We can assume that the input string contains only lowercase letters. If the encoding process does not make the string shorter, then do not encode that string.So, if the input is like "aaaaa", then the output will be ... Read More

Suppose we have two non-empty strings s1 and s2 (maximum 100 characters) and two numbers n1 and n2 both are in range 0 to 106. Now suppose the strings S1 and S2, where S1=[s1, n1] and S2=[s2, n2].S = [s, n] defines the string S which consists of n connected strings s. As an exdample, ["ab", 4] ="abababab".On the other hand, we cal also define that string s1 can be obtained from string s2 if we remove some characters from s2 such that it becomes s1. So, "abc" can be obtained from "abdbec" based on the definition, but it can ... Read More

Suppose a group of friends went on holiday and sometimes they lent each other money. So as an example, Amit paid for Bikram's lunch for $10. Then later Chandan gave Amit $5 for a taxi fare. We have to design a model where each transaction is taken as a tuple (x, y, z) which means person x gave person y $z.Assuming Amit, Bikram, and Chandan are person 0, 1, and 2 respectively the transactions can be represented as [[0, 1, 10], [2, 0, 5]]. If we have a list of transactions between a group of people, we have to find ... Read More

Suppose we have a N-ary tree. We have to encode that tree into one binary. We also have to make deserializer to deserialize the binary tree to N-ary tree.So, if the input is likethen the output will beTo solve this, we will follow these steps −Define a function encode(), this will take root, if root is valid, then −return nullnode = new tree node with value of rootif size of children of root is not 0, then −left of node := encode(children[0] of root)curr = left of nodefor initialize i := 1, when i < size of children of root, ... Read More

Suppose we have one N-ary tree and we have to serialize and deserialize them. As we know that the serialization is the process of converting a data structure or object into a sequence of bits so we can store them in a file or memory buffer, and that can be reconstructed later in the same or another computer environment.Here we have to devise an algorithm to serialize and deserialize an N-ary tree. The N-ary tree is a rooted tree in which each node has no more than N children.So, if the input is likethen the output will be Serialize: 1 ... Read More

Suppose we have a set of words (all are unique), we have to find all word squares and we can build from them. Here a sequence of words forms a valid word square if the kth row and column read the exact same string, where 0 ≤ k < maximum of numRows and numColumns. So as an example, the word sequence ["ball", "area", "lead", "lady"] will construct a word square because each word reads the same both horizontally and vertically.ballarealeadladySo, if the input is like ["area", "lead", "wall", "lady", "ball"], then the output will be [[ "wall", "area", "lead", "lady"], ... Read More

Suppose we have a string such as "word" and that contains the following abbreviations: ["word", "1ord", "w1rd", "wo1d", "wor1", "2rd", "w2d", "wo2", "1o1d", "1or1", "w1r1", "1o2", "2r1", "3d", "w3", "4"]. We also have a target string and a set of strings in a dictionary, we have to find an abbreviation of this target string with the smallest possible length such that it does not conflict with abbreviations of the strings in the dictionary. Here each number or letter in the abbreviation is considered as length = 1. So as an example, the abbreviation "a32bc" is of length = 4.So, if ... Read More

Suppose we have N axis-aligned rectangles, we have to check whether they all together form an exact cover of a rectangular region or not. Here each rectangle is represented as a bottom-left point and a top-right point. So a unit square is represented as [1, 1, 2, 2]. (bottom-left point is (1, 1) and top-right point is (2, 2)).So, if the input is like rectangles = [[1, 1, 3, 3], [3, 1, 4, 2], [3, 2, 4, 4], [1, 3, 2, 4], [2, 3, 3, 4]], then the output will be true as all 5 rectangles together form an exact ... Read More

Suppose we have a non-empty string s and an integer k; we have to rearrange the string such that the same characters are at least distance k from each other. Given strings are in lowercase letters. If there is no way to rearrange the strings, then we will an empty string.So, if the input is like s = "aabbcc", k = 3, then the output will be "abcabc" this is because same letters are at least distance 3 from each other.To solve this, we will follow these steps −ret := an empty stringDefine one map mn := size of sfor ... Read More

Suppose we have a string; we have to calculate the length of the longest substring T that contains at most k distinct characters.So, if the input is like s = "eceba", k = 2, then the output will be 3 as T is "ece" which its length is 3.To solve this, we will follow these steps −ans := 0Define one map mn := size of sx := 0for initialize j := 0, i := 0, when j < n, update (increase j by 1), do −(increase m[s[j]] by 1)if m[s[j]] is same as 1, then −(increase x by 1)while (x > k and i k && i