Print k different sorted permutations of a given array
Given an array arr[] containing N integers, the task is to print k different permutations of indices such that the values at those indices form… Read More »
Category Archives: Combinatorial
Number of trailing zeroes in base 16 representation of N!
Given an integer N, the task is to find the number of trailing zeroes in the base 16 representation of the factorial of N. Examples:… Read More »
Sum of all Submatrices of a Given Matrix
Given a NxN 2-D matrix, the task to find the sum of all the submatrices. Examples: Input : arr[] = {{1, 1}, {1, 1}}; Output… Read More »
Iterating over all possible combinations in an Array using Bits
There arises several situations while solving a problem where we need to iterate over all possible combinations of an array. In this article, we will… Read More »
Python program to get all subsets of given size of a set
Given a set, write a Python program to generate all possible subset of size n of given set within a list. Examples: Input : {1,… Read More »
Java Program to print distinct permutations of a string
Given a string str, the task is to print all the distinct permutations of str. A permutation is an arrangement of all or part of… Read More »
An application on Bertrand’s ballot theorem
Given the number of ‘X’ and ‘Y’ in a string which consists of characters from the set {‘X’, ‘Y’}, the task is to find the… Read More »
Ways to divide a binary array into sub-arrays such that each sub-array contains exactly one 1
Give an integer array arr[] consisting of elements from the set {0, 1}. The task is to print the number of ways the array can… Read More »
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 »
Number of Simple Graph with N Vertices and M Edges
Given two integers N and M, the task is to count the number of simple undirected graphs that can be drawn with N vertices and… Read More »
Arrange first N natural numbers such that absolute difference between all adjacent elements > 1
Given an integer N. The task is to find the permutation of first N natural numbers such that the absolute difference between any two consecutive… Read More »
Number of unique pairs in an array
Given an array of N elements, the task is to find all the unique pairs that can be formed using the elements of a given… Read More »
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 »
K length words that can be formed from given characters without repetition
Given an integer k and a string str consisting of lowercase English alphabets, the task is to count how many k character words (with or… Read More »
Maximum number of 3-person teams formed from two groups
Given two integers N1 and N2 where, N1 is the number of people in group 1 and N2 is the number of people in group… Read More »