Find duplicates Characters in the given String
Objective: Given a string, write an algorithm to find all the duplicate characters in the string and print its count. Example: Input String: tutorial horizon Output: Duplicate Characters: r – 2 t – 2...
Category: Beginner
Java program to find the largest element in array
Objective– Given an array of numbers, write a java program to find the largest element in the given array. Example: int [] a = {1, 5, 3, 9, 2, 8, 2} Largest Element: 9...
Find three smallest elements in a given array
Objective: Given an array of integers, write an algorithm to find the three smallest elements in the array. Example: Int [] a = { 6, 8, 1, 9, 2, 10}; Output: 1, 2, 6...
Stack Java Class – Explained
Earlier we saw about Stack and its implementation using Linked List. Java has a built in class for Stack. In this article we will discuss about it in detail. First brief about Stack. What...
Infix, Postfix and Prefix Notations/Expressions
Infix, Postfix and Prefix notations are most common ways of writing expressions. Infix notation: Example: (A+B) Infix notation is commonly used in arithmetic formula or statements, the operators are written in-between their operands. An...
Count Set bits in a given Number
Objective: Given a Number, find all the set bits in that number. Example: Number: 23 Set bits: 4 (10111) Number: 15 Set bits: 4 (1111) Number: 21 Set bits: 3 (10101) Approach: Check the...
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...
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...