Intermediate

Find all possible combinations with sum K from a given number N(1 to N) with the repetition of numbers is allowed

by

Objective: Given two integers N and K, Write an algorithm to find possible combinations that add to K, from the numbers 1 to N.  Condition: An integer from 1 to N can be repeated any number of times in combination. Example: N = 5 K = 3 Output: [1, 1, 1] [1, 2] [3] N … Read more Find all possible combinations with sum K from a given number N(1 to N) with the repetition of numbers is allowed

Construct the largest number from the given array.

by

Objective: Given an array of integers, write an algorithm to construct the largest number possible by appending the array elements.  Example: Given Input: [7, 78] Largest Number Possible: 787 Explanation: two possibilities are 778 and 787. 787 is larger than 778. Given Input: [25, 42, 39] Largest Number Possible: 423925 Approach:  Normal sorting in descending … Read more Construct the largest number from the given array.

Given an array, find three-element sum closest to Zero

by

Objective: Given an array of integers, find the sum of any three elements which is closest to zero. The array may contain positive and negative elements.  Example:  Given Input: [-1, 4, -2, 5, 10, -5] Minimum Sum with three elements is: 1 Explanation:  -1, 4, -2 sums to -1  Given Input: [-1, 4, -2, 5, … Read more Given an array, find three-element sum closest to Zero

Given an array, print all unique subsets with a given sum.

by

Objective: Given an array of integers and number N, Write an algorithm to find and print all the subsets of the array for which sum is equal to N. Example: input [] = {6,2,7,8,2,4,1,3,7,5} Sum = 8 Output: [1, 2, 2, 3] [1, 2, 5] [1, 3, 4] [1, 7] [2, 2, 4] [2, 6] … Read more Given an array, print all unique subsets with a given sum.

Sum of length of subsets which contains given value K and all elements in subsets are less than equal to K.

by

Objective: Given an array of numbers and integer K. Your task is to find lengths of all the subsets which contain value K and all elements in the subset are less than equal to K. Example: Given Input: [1, 5, 2, 3, 8, 6, 2, 4, 9, 5, 2], and K = 5 Length of … Read more Sum of length of subsets which contains given value K and all elements in subsets are less than equal to K.

Replace array elements with maximum element on the right.

by

Objective: Given an array of integers, write a program to replace its elements with the maximum element on the right side from their respective positions.  Note: If the element is equal to the maximum element on the right, replace it with 0. Example: Original Array: [2, 5, 1, 6, 3, 4] Output: [6, 6, 6, … Read more Replace array elements with maximum element on the right.

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

by

Objective: Given an integer N, Write an algorithm to select numbers from 1 to 9 and make combinations such that its sum to N.  Example: N= 5 Output:  [1, 4] [2, 3] [5] N =12 [1, 2, 3, 6] [1, 2, 4, 5] [1, 2, 9] [1, 3, 8] [1, 4, 7] [1, 5, 6] … Read more Find all unique combinations of numbers (from 1 to 9 ) with sum to N

Activity Selection Problem

by

Objective: The activity selection problem is a combinatorial optimization problem concerning the selection of non-conflicting activities to perform within a given time frame, given a set of activities each marked by a start time (si) and finish time (fi). The problem is to select the maximum number of activities that can be performed by a … Read more Activity Selection Problem

Check If Given Undirected Graph is a tree

by

Objective: Given an undirected graph, Write an algorithm to determine whether its tree or not. An undirected graph is a tree if it has properties mentioned below There is no cycle present in the graph. The graph is connected. (All the vertices in the graph are connected) Example: Recommended articles to read before continue reading … Read more Check If Given Undirected Graph is a tree

Check the completeness of given binary tree | Set 2 – Using Level Order Traversal

by

Objective: Given a binary tree, write an algorithm to determine whether the tree is complete or not using Level order traversal. Earlier we had solved this problem by counting the number of nodes in the tree. (Read – Check the completeness of given binary tree | Set 1 – Using Node Count. In this article, … Read more Check the completeness of given binary tree | Set 2 – Using Level Order Traversal

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

by

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

Check the completeness of given binary tree | Set 1 – Using Node Count

by

Objective: Given a binary tree, write an algorithm to determine whether the tree is complete or not.  Complete Binary Tree: A binary tree T with n levels is complete if all levels except possibly the last are completely full, and the last level has all its nodes to the left side. Example:  Below is an … Read more Check the completeness of given binary tree | Set 1 – Using Node Count

Number of Islands using BFS

by

Objective: Given a 2d grid map of ‘1’s (land) and ‘0’s (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. Assume all four edges of the grid are all surrounded by water. Given such grid, write an algorithm using Breadth-First Search(BFS) to … Read more Number of Islands using BFS

Longest substring with at most K unique characters

by

Objective: Given a string, write an algorithm to find the longest substring with at most K characters. Example: Input: aabbaacdeeeeddded, K = 3 Output: Longest substring with 3 most unique characters is: cdeeeeddded with length 11 Input: abcddefabc, K = 4 Output: Longest substring with 4 most unique characters is: abcdd with length 5 Input: … Read more Longest substring with at most K unique characters

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

by

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