Case-specific sorting of Strings in O(n) time and O(1) space
Given a string str consisting of uppercase and lowercase characters. The task is to sort uppercase and lowercase characters separately such that if the ith… Read More »
Tag Archives: frequency-counting
Distinct strings such that they contains given strings as sub-sequences
Given two strings str1 and str2 of lengths M and N respectively. The task is to find all the distinct string of length M +… Read More »
Partiton the string in two parts such that both parts have at least k different characters
Given a string of lowercase English alphabets and an integer 0 < K <= 26. The task is to divide the string into two parts… Read More »
Find the first duplicate element in the linked list
Given a linked list. Find the first element from the left which appears more than once. If all the elements are unique then print -1.… Read More »
Number of triplets such that each value is less than N and each pair sum is a multiple of K
Given two integers N and K. Find the numbers of triplets (a, b, c) such that 0 ≤ a, b, c ≤ N and (a… Read More »
Minimum deletions required such that any number X will occur exactly X times
Given an array arr[] of N integers, the task is to find the minimum deletions required such that frequency of arr[i] is exactly arr[i] in… Read More »
Find the maximum number of elements divisible by 3
Given an array of size N. The task to find the maximum possible number of elements divisible by 3 that are in the array after… Read More »
Design a stack which can give maximum frequency element
Given N elements and the task is to implement a stack which removes and returns the maximum frequency element on every pop operation. If there’s… Read More »
Count pairs with set bits sum equal to K
Given an array arr[] and an integer K, the task is to count the pairs whose sum of set bits is K Examples: Input: arr[]… Read More »
Find minimum difference between any two elements | Set 2
Given an unsorted array arr[] of size n, the task is to find the minimum difference between any pair in the given array. Input: arr[]… Read More »
Largest sub-string where all the characters appear at least K times
Given a string str and an integer K, the task is to find the length of the longest sub-string S’ such that every character in… Read More »
Queries to find the first non-repeating character in the sub-string of a string
Given a string str, the task is to answer Q queries where every query consists of two integers L and R and we have to… Read More »
Longest prefix in a string with highest frequency
Given a string, find a prefix with the highest frequency. If two prefixes have the same frequency then consider the one with maximum length. Examples:… Read More »
Find the maximum length of the prefix
Given an array arr[] of N integers where all elements of the array are from the range [0, 9] i.e. a single digit, the task… Read More »
Length of the largest substring which have character with frequency greater than or equal to half of the substring
Given a string S consisting of character from ‘a’ to ‘z’. The task is to find the length of the largest substring of S which… Read More »
