Given an array arr[] and a number K, the task to find the maximum distance between two elements whose absolute difference is K. If it is not possible to find any maximum distance then print “-1”....
Given an array arr[] consisting of N integers, the task is to find the maximum element with the minimum frequency....
Given an array arr[] of size N and an integer S, the task is to find the count of quadruplets present in the given array having sum S....
Given a string str, the task is to find the number of distinct substrings that are placed consecutively in the given string....
Given string S consists of lowercase and uppercase letters, the task is to find the number of substrings having an equal number of lowercase and uppercase letters....
Given a number N, the task is to find the number of quadruples such that a2 + b2 = c2 + d2 where (1 <= a, b, c, d <= N)....
Given an array arr[] consisting of N integers and a positive integer K, the task is to count the number of subarrays having exactly K elements occurring at least twice....
The putIfAbsent(Key, value) method of Hashtable class which allows to map a value to a given key if given key is not associated with a value or mapped to null. A null value is returned if such key-value set is already present in the HashMap....
Given a binary tree, a target node and a positive integer K on it, the task is to find the sum of all nodes within distance K from the target node (including the value of the target node in the sum)....
The Hashtable class represents a collection of key-and-value pairs that are organized based on the hash code of the key. The key is used to access the items in the collection....
Hashtable class implements a hash table, which maps keys to values. Any non-null object can be used as a key or as a value. To successfully store and retrieve objects from a hashtable, the objects used as keys must implement the hashCode method and the equals method....
The toString() method in the Hashtable class in Java returns a string representation of the key-value mappings contained in the hashtable. The string is in the form of a comma-separated list of key-value pairs enclosed in curly braces....
