Check if array contains all unique or distinct numbers.
Objective: Given an array of integers, write a program to check if array contains all unique numbers. Example: Integer [] arrA = { 1, 2, 3, 6, 4, 9, 8}; Output: Array has all...
Category: Beginner
Product of all Unique elements in a given array.
Objective: Given an array of integers which contains duplicates as well. Write a program to find the product of all unique elements in the array. This problem is also referred as find the product...
Reverse a given number – Java Code
Objective: Given a number, write a java program to reverse a number Example: Given Number: 1234 Output: 4321 Given Number: 1020 Output: 201 Approach: Using loop Keep divide the number by 10 and add...
Check if given number is perfect square – O(√N) Solution
Objective: Given a number, write a program to check if given number is perfect sqaure. Example: N = 16 Output: True N = 32 Output: False Approach: Naive Approach: If N = 1 return...
Find first three largest elements in a given array
Objective: Given an array of integers, write an algorithm to find the first three largest elements in the array. Example: Int [] a = { 6, 8, 1, 9, 2, 1, 10}; Output: 10,...
Selection Sort – Java Implementation
What is Selection Sort?? Selection sort is a simple sorting algorithm that builds the sorted array one item at a time. This sorting is efficient for small data sets, not efficient for large data...
Print Number with its Sign in Java
Sometimes we need to print the numbers with its sign irrespective of number is positive (+) or negative(-). Example: X = 5, print = +5 Y = -8, print = -8 Say we need...
Valid Brackets – Part 2 | Stack Method
Objective: Given a string containing just the characters ( , ) determine if the input string is valid. Example: ()()(()(()))() valid: true )()()( valid: false ()()) valid: false Approach: Earlier we discussed the solution which keeps...
Find the roots of Quadratic Equation – Java Program
Quadratic equation is in the form = ax2 + bx + c Discriminant (d) = b2 – 4ac Then roots are calculates using the equations below Root_1 = (-b + √d)/2a Root_2 = (-b...
Given two strings validate the output string
Objective: Given two input strings and one output strings, validate if output string contains all the characters from both the input strings. Example: Input1 = “boy”, Input2 = “girl”, output = “gboilry” Result =...
Find Largest and Smallest word in a given String
Objective: Given a String, write a program to find largest and smallest word in it. Example: Input String: test Smallest Word: test Largest Word: test —————— Input String: This problem is solved at Algorithms...
Find two smallest elements in a given array
Objective: Given an array of integers, write an algorithm to find the two smallest elements in the array. Example: Int [] a = { 6, 8, 1, 9, 2, 10}; Output: 1, 2 Int...
Front and Back Search in an Array
Objective: Given an unsorted array of numbers and a number ‘x’, write a java program to search the number ‘x’ in the array and return its index else return -1. Example: Int [] a...
Print all Unique elements in a given array
Objective: Given an array of integers which contains duplicates as well. Write a program to print all unique elements in the array. This problem is also referred as print all distinct elements in the...
Multiply with power of 2 without using pow() or * operator
Objective: Given a number n and k, Calculate n * k2 without using pow() or *operator. Example: N = 3, k = 4 N*k2 = 48 Approach: Bit Manipulation Left shift the number N...