## Total possible solutions to linear equation of k variables

Given a linear equation of k variables, count total number of possible solutions of it.

Coding made easy

Given a linear equation of k variables, count total number of possible solutions of it.

Given a binary tree, write an efficient algorithm to invert binary tree.

Given an integer, swap two bits at given positions in binary representation of it.

Given an array, reverse every group of consecutive m elements in given subarray of it.

Given an array of integers, find a subset in it that has maximum product of its elements.

Given an unsorted array of integers, print all pairs with given difference k in it without using any extra space.

Given an unsorted array of integers, print all pairs with given difference k in it.

Given a number, find out if it is even or odd without using any conditional statement (if-else) or ternary operator.

Given an array of integers, duplicates are present in it in such a way that all duplicates appear even number of times except one which appears odd number of times. Find that odd appearing element in linear time and without using any extra memory.

Quickselect is a selection algorithm to find the kth smallest element in an unordered list. It is closely related to the quicksort sorting algorithm.

The longest decreasing subsequence problem is to find a subsequence of a given sequence in which the subsequence’s elements are in sorted order, highest to lowest, and in which the subsequence is as long as possible.

In cryptography, Triple DES (3DES) is a symmetric-key block cipher, which applies the Data Encryption Standard (DES) cipher algorithm three times to each data block.