Combinatorial - Hard Articles

Number of subsets with sum divisible by M | Set 2

Given an array arr[] of N integers and an integer M, the task is to find the number of non-empty subsequences such that the sum… Read More

divisibility

subset

Arrays

Combinatorial

DSA

Dynamic Programming

Sum of subsets of all the subsets of an array | O(N)

Given an array arr[] of length N, the task is to find the overall sum of subsets of all the subsets of the array.Examples: Input:… Read More

subset

Arrays

Backtracking

Combinatorial

DSA

Number of K length subsequences with minimum sum

Given an array arr[] of size N and an integer K, the task is to find the number of K length subsequences of this array… Read More

subsequence

Arrays

Combinatorial

DSA

Mathematical

Count ways to divide circle using N non-intersecting chord | Set-2

Given a number N. The task is to find the number of ways you can draw N chords in a circle with 2*N points such… Read More

catalan

Combinatorial

DSA

Greedy

Mathematical

Mobile Numeric Keypad Problem | Set 2

Given the mobile numeric keypad. You can only press buttons that are up, left, right or down to the current button or can choose to… Read More

Combinatorial

DSA

Dynamic Programming

Iterative approach to print all permutations of an Array

Given an array arr[] of size N, the task is to generate and print all permutations of the given array. Examples: Input: arr[] = {1,… Read More

permutation

Arrays

Combinatorial

DSA

Dynamic Programming

Number of ways to paint a tree of N nodes with K distinct colors with given conditions

Given a tree with N nodes and a number K. Paint every node of the tree in one of the K available colors. Count and return… Read More

Combinatorial

DSA

Tree

Number of ways to reach the end of matrix with non-zero AND value

Given an N * N matrix arr[][] consisting of non-negative integers, the task is to find the number of ways to reach arr[N – 1][N… Read More

Algorithms

Bit Magic

Combinatorial

DSA

Dynamic Programming

Matrix

Recursion

Generate all permutations of a string that follow given constraints

Given a string, generate all permutations of it that do not contain ‘B’ after ‘A’, i.e., the string should not contain “AB” as a substring.… Read More

Backtracking

Combinatorial

DSA

Misc

Strings

Number of ways to arrange K different objects taking N objects at a time

Given two integers K and N, the task is to count the number of ways to arrange K different objects taking N objects at a… Read More

factorial

Combinatorial

Competitive Programming

DSA

Mathematical

Product of all Subsequences of size K except the minimum and maximum Elements

Given an array A[] containing N elements and an integer K. The task is to calculate the product of all elements of subsequences of size… Read More

Algorithms

C++ Programs

Combinatorial

Competitive Programming

DSA

Sorting

Count pairs of non-overlapping palindromic sub-strings of the given string

Given a string S. The task is to count the non-overlapping pairs of palindromic sub-strings S1 and S2 such that the strings should be S1[L1…R1]… Read More

palindrome

substring

Combinatorial

DSA

Dynamic Programming

Strings

Sum of bitwise AND of all submatrices

Given an NxN matrix, the task is to find the sum of bit-wise AND of all of its rectangular sub-matrices. Examples: Input : arr[][] =… Read More

Bitwise-AND

Arrays

Bit Magic

Combinatorial

Competitive Programming

DSA

Dynamic Programming

Mathematical

Matrix

Stack

Number of submatrices with all 1s

Given an N*N matrix containing only 0s and 1s, the task is to count the number of submatrices containing all 1s. Examples: Input : arr[][]… Read More

Constructive Algorithms

Algorithms

Combinatorial

DSA

Mathematical

Matrix

Stack

Count of sub-sets of size n with total element sum divisible by 3

Given an integer n and a range [l, r], the task is to find the count of total sub-sets of size n with integers from… Read More

Advanced Data Structure

Algorithms

Combinatorial

Competitive Programming

DSA

Dynamic Programming

Mathematical

National Instruments Interview Experience (Off-campus)

Hiring was for Internship. The first round was a coding test on HackerEarth. There were two questions. Both carried 100 marks each. 1.Min-Max Weighted Edge… Read More

C Language

C Programs

C#

C# Programs

C++

C++ Programs

C/C++ Puzzles

Combinatorial

Competitive Programming

CS - Placements

DSA

Engineering Mathematics

Engineering Mathematics Questions

Experiences

Graph

Internship

Interview Experiences

Mathematical

Matrix

Pattern Searching

Programming Language

Tree

Ways to paint N paintings such that adjacent paintings don’t have same colors

Given two integers n and m, where n represent some paintings numbered from 1 to n and m represent some colours 1 to m with… Read More

maths-power

Algorithms

Combinatorial

DSA

Mathematical

Count of Numbers in a Range divisible by m and having digit d in even positions

Given a range represented by two positive integers l and r and two integers d and m. Find the count of numbers lying in the… Read More

digit-DP

Technical Scripter 2018

Algorithms

Combinatorial

Competitive Programming

DSA

Dynamic Programming

Recursion

Count ordered pairs of positive numbers such that their sum is S and XOR is K

Given a sum and a number . The task is to count all possible ordered pairs (a, b) of positive numbers such that the two positive integers… Read More

Bitwise-XOR

setBitCount

Technical Scripter 2018

Bit Magic

Combinatorial

DSA

Mathematical

Count unique subsequences of length K

Given an array of N numbers and an integer K. The task is to print the number of unique subsequences possible of length K. Examples:… Read More

Algorithms

C++ Programs

Combinatorial

Competitive Programming

DSA

Recursion

Searching