Decimal to Binary

Given a decimal number, convert that number to its binary representation. Example:  Number: 5, binary representation: 101 Number: 8, binary representation: 1000 Number: 105, binary representation: 1101001 Solution:  Initialize a result string and while the given number is greater than 0, keep dividing it by 2 and append the remainder of division to the result … Read more

Valid Pickup and Delivery options

Given N orders, each order consists of pickup and delivery services, means delivery of a particular service will after the pick up of the same service so the sequence pickup/delivery such that delivery(i) is after pickup(i). Write a program to count all valid pickup/delivery possible sequences Since the answer may be too large, return it … Read more

The largest number can be formed from the given number

Given a number write an algorithm to construct the largest number possible by using the digits of given number. Given number could be a negative number as well.  Example: Given Input: 34277765 Output: 77765432 Given Input: -342765 Output: -234567 Given Input: 0 Output: 0 Given Input: 2034 Output: 4320 Approach: Sorting Check if the given … Read more

Construct the Largest number from the given digits

Given a set of digits, write an algorithm to construct the largest number possible by appending the given digits. Example: Given Digits: [9, 1, 9, 2, 8, 4, 2] largest number: 9984221 Given Digits: [1, 2, 5, 6, 7] largest number: 76521 Approach: Sorting Sort the given array in descending order. Initialize result = 0. … Read more

Numbers with prime set bits in a given range using Sieve of Eratosthenes Algorithm

Objective: Given a range, find all the numbers in the range which has prime set bits using Sieve of Eratosthenes Algorithm. Earlier we had seen a similar problem -Numbers with prime set bits in a given range solved in the naive approach. in this algorithm, we will improve the time complexity using the Sieve of … Read more

Collatz Conjecture – Maximum Steps takes to transform (1, N) to 1.

Objective: Given a number N, write an algorithm to find the maximum number of steps it takes to transform (1, N) to 1 using Collatz Conjecture.  The Collatz conjecture is a conjecture in mathematics which states that no matter what value of Positive Number N, If the below sequence is followed then the sequence will … Read more

Find all unique combinations of exact K numbers (from 1 to 9 ) with sum to N

Objective: Given two integers N and K. Write an algorithm to find all the combinations of k numbers which sum to N.  Conditions:  All K numbers must be between 1 and 9 and unique. All numbers in K are positive. Example: N= 5 K=2 Output: [1, 4] [2, 3] N =12 K=3 Output: [1, 2, … Read more