In this problem, we need to find the maximum consecutive zeros at the start and end of string rotation. We can follow two approaches to solve the problem. The first approach is to find all rotations of the given string and count start and end zeros. The second approach is to count the maximum consecutive zeros in the string and get the answer. Problem statement – We have given the binary string named str of size equal to ‘len’. We need to count the maximum number of consecutive zeros at the start and end of any rotation of the string. ... Read More

In this problem, we need to perform the given queries on the string. We can solve the problem by making the rotations of the string differently and accessing the required characters using their index. Problem statement – We have given string str of length N and array ‘que’ of size M containing queries. We need to perform the queries given in the array according to the below conditions. (1, x) – Make x left rotations of the string. (2, x) – Show the xth character in the output. Sample examples Input que[][2] = {{1, 2}, {2, 1}, ... Read More

Queue and Deque both are linear data structures that are defined in STL of C++ programming language. Queue works on the principle of the first in first out, the element added to the queue first will be removed first, on the other hand, deque has properties to add an element either at the first index or last index, and similarly, any one of them can be removed. We will see the code of both data structures to get the exact differences. Basics of Queue As we have seen above, the queue is based on the concept of the first in ... Read More

In this problem, we need to check whether the given sentence is tautogramic. We can say any sentence is tautogramic if all words have the same starting character. We will learn two approaches to solving the problem. The logic to solve the problem is to check all words' first characters. If any word has a mismatched first character, we can say the sentence is not tautogramic. Problem statement – We have a string containing the N characters. We need to check whether the given string is tautogramic or not. Note – The tautogramic contains all words starting with the same ... Read More

Binary Tree is a non-linear data structure. It has a maximum of two children and each node contain three things that are data value, left and right pointer. The top node is called the root node and the last node which does contain any children is called the leave node. In this problem, we have given a binary tree. It has N nodes in the range from 1 to N (both inclusive) and our task is to find the distance of each node of a binary tree from the root node using BFS. Examples Let's see examples with explanations below ... Read More

We are given an array of strings and each string represents a number that could be more than the range of the maximum integer limit. We have to find the largest and the smallest element from the given array. We cannot use the simple less than or greater than operators to check which string is greater as it won't works find with the string so we will make our own comparison function. Example Let's understand the problem with the help of an example − Input string arr[] = {"2", "3", "12", "23", "22", "0", "7"} Output The smallest element ... Read More

A substring is a string that can be achieved from the given string by removing some characters from the beginning and end of the string (possibly none or all). We are given a string and three characters and have to find the longest substring that contains all the three given characters in the sequence of c1, c2, and c3 starting with c1 and ending with c3. Also, the given characters may be the same but we string must contain different characters for each of them. Input string str = "abacdeab" char c1 = a char c2 = b char ... Read More

We are given a string of length S and given an another number n which represents the length of the strings which might contains S as the subsequence. We have to find the number of unique strings of length N which contains S as the subsequence, where a subsequence is the set of characters from the given string which may be all the characters or not and they not need to be continuous. Sample Examples Input string str = "xyz" int n = 3 Output 1 Explanation There is only one string of length 3 that contains the ... Read More

A subsequence is a string that can be achieved from another string by removing some (possibly none or all) from a given string that may not be continuous. We are given a string and have to find the number of subsequences that are greater than equal to the given string Y and less than equal to another given string Z. We will use dynamic programming to solve the problem as brute force will take exponential time. Brute Force Approach The brute forces approach is to find all the subsequences of the given string X and then check if they are ... Read More

A substring is the continuous sequence of the character from the given string which can be achieved by removing some character from the front and the end of the substring (possibly all or none). We are given a binary string and we have to find the length of the longest substring that contains at most X number zeros and Y number of ones where X and Y are given inputs. Sample Examples Input  string str = "101011"; int x = 1; int y = 2; Output The length of the longest substring with at most X zeroes and ... Read More