## Given an array of ints, return true if the value 3 appears in the array exactly 3 times, and no 3’s are next to each other.

Following are the test cases Test cases Result Status haveThree({12,3,4,3,88,3}) true OK haveThree({22,3,3,3,17,3}) false OK haveThree({3,4,3,6,3,7}) true OK Java solution package test; public class Program20...

Continue reading

## Given an array of ints, return true if the sum of all the 2’s in the array is exactly 8.

Following are the test cases Test cases Result Status sum28({10,20,30,40,50,60,2}) false OK sum28({2,10,7,2,2,2}) true OK sum28({5,6,1,2,2,2}) false OK Java solution package test; public class Program19 { public...

Continue reading

## Given a string and an int n, return a string made of the first and last ‘ n’ chars from the string. The string length will be at least n.

Following are the test cases Test cases Result Status nTwice(Hello,2) Helo OK nTwice(Chocolate,3) Choate OK nTwice(java,1) ja OK Java solution package test; public class Program18 { public static void...

Continue reading

## Given an “out” string length 4, such as “<<>>”, and a word, return a new string where the word is in the middle of the out string, e.g. “<>”

Following are the test cases Test cases Result Status makeOutWord(<<>>,Yay) <<Yay>> OK makeOutWord([[]],Word) [[Word]] OK makeOutWord([((JAVA))] ((JAVA)) OK Java solution package...

Continue reading

## Return true if the given string contains 1 or 3 ‘e’ chars. Otherwise return false.

Following are the test cases Test cases Result Status stringE(Hello) true OK stringE(Heelele) false OK stringE(Heelle) true OK Java solution package test; public class Program16 { public static void...

Continue reading

## Return true if the array contains, somewhere, three increasing adjacent numbers like …. 4, 5, 6, … or 23, 24, 25.

Following are the test cases Test cases Result Status tripleUp({1,2,3,7,5,9}) true OK tripleUp({1,4,5,6,2}) true OK tripleUp({1,2,4,5}) false OK Java solution package test; public class Program15 { public static...

Continue reading

## Pass an int as parameter. Find the sum of the digits in the number and return it.

Following are the test cases Test cases Result Status sumOfDigits(144) 9 OK sumOfDigits(457) 16 OK sumOfDigits(345) 12 OK Java solution package test; public class Program14 { public static void main(String[]...

Continue reading

## Given a string of even length, return the first half. So the string “WooHoo” yields “Woo”.

Following are the test cases Test cases Result Status firstHalf(HelloThere) Hello OK firstHalf(abcdef) abc OK firstHalf(Word) Wo OK Java solution package test; public class Program13 { public static void...

Continue reading

## Given an array of ints, return true if one of the first 4 elements in the array is a 9. The array length will be greater than 4.

Following are the test cases Test cases Result Status arrayFront9({1,2,9,3,4}) true OK arrayFront9({9,2,3,4,56}) true OK arrayFront9({2,3,4,5}) false OK Java solution package test; public class Program12...

Continue reading

## Write a program to generate Fibonacci series of limit number of elements.

Following are the test cases Test cases Result Status generateFibSeries(5) {0,1,1,2,3} Ok generateFibSeries(7) {0,1,1,2,3,5,8} Ok generateFibSeries(10) {0,1,1,2,3,5,8,13,21,34} Ok Java solution public class Program11...

Continue reading

## Given a string, return a new string where the first and last chars have been exchanged

Test cases Test cases Expected Result frontBack(abcd) dbca OK frontBack(Bee) eeB OK frontBack(MazE) EazM OK Java solution: public class Program10 { public static void main(String[] args)...

Continue reading

## Pass an int array and an int and do a search of the second parameter in the first, and return true/false.

Test cases Test cases Expected Result searchElement({33,44,21,98,27,94},21) true OK searchElement({1232,432,546,980,984},980) true OK searchElement({3,4,9,87,29},2) false OK Java solution: public class Program9...

Continue reading

## Given an array of ‘N’ elements .Return the sum of all array elements

Test cases Test cases Expected Result arraySum({5,5,5,5,5}) 25 OK arraySum({1,3,4,7,8}) 23 OK arraySum({100,200,300}) 600 OK Java solution: public class Program8 { public static void main(String[] args) { int a[]...

Continue reading

## Accept a string as parameter. Find out how many consonants present in it.

Test cases: Test cases Expected Result countConsonents(instanceof is for references only) –> 18 OK countConsonents(Object Oriented) –> 8 OK countConsonents(Design Patterns88)...

Continue reading

## Pass a string as parameter. Find out how many vowels present in it

Test cases: Test cases Expected Result countVowels(instanceif is for references only) 11 OK countVowels(Object Oriented) 6 OK countVowels(Design Patterns) 4 OK Java solution: public class Program6 { public static...

Continue reading

## Given two strings, append them together (known as “concatenation”) and return the result.

Test cases: Test cases Expected Result stringConcat(Hello,World) Hello World OK stringConcat(Code,ranch) Code ranch OK stringConcat(Web,Application) Web Application OK Java solution: public class Program5 { public...

Continue reading

## Return true if the given non-negative number is a multiple of 3 or a multiple of 5

Test cases: Test cases Expected Result or35(15) true OK or35(8) false OK or35(12) true OK Java solution: public class Program4 { public static void main(String[] args)...

Continue reading

## Test whether the number is divisible by 7 or not

Test cases: Test cases Expected Result isDivisibleBy7(17) false OK isDivisibleBy7(77) true OK isDivisibleBy7(12) false OK Java solution: public class Program3 { public static void main(String[] args)...

Continue reading

## Check the given number is odd or even

Test cases: Test cases Expected Result testOddEven(12) even OK testOddEven(3) odd OK testOddEven(-55) odd OK Java solution: package test; public class Program2 { public static void main(String[] args)...

Continue reading

## Pass two ints as parameter and return the sum of numbers.

Test cases: Test cases Expected Result sum(10,12) 22 OK sum(1,2) 3 OK sum(2147483647,1) 2147483648 OK Java solution: public class Sum { public static void main(String[] args) { Sum.sum(10, 12); Sum.sum(1...

Continue reading

## Interview Program – Matrix

Print matrix in Z form. Input: mat[][] = {1, 2, 3, 4, 5, 6, 7, 8, 9} Output: 1 2 3 5 7 8 9 public class PrintTheMatrixOrder { public static void printTheMatrix(int mat[][]) { for (int i = 0; i < mat.length; i++)...

Continue reading

## Interview Program

Print all jumping numbers smaller than or equal to x. Input: x = 105 Output: 0 1 2 3 4 5 6 7 8 9 10 12 21 23 32 34 43 45 54 56 65 67 76 78 87 89 98 101 Note: A number is called as a jumping number if all adjacent digits in it...

Continue reading

## Interview Program – Matrix

Find if there is a rectangle in binary matrix with corners as 1. Input: mat[][] = {{1, 0, 0, 1, 0}, {0, 0, 1, 0, 1}, {0, 0, 0, 1, 0}, {1, 0, 1, 0, 1}} Output: YES Note: as there exists –             1 0 1        ...

Continue reading

## Interview program – Matrix

Print squares of diagonal elements in O(n) time complexity Input: 1 2 3 4 5 6 7 8 9 Output: 1 25 81 9 25 49 public class SquareOfDiagonal { static void printDiagonalSquare(int[][] mat) { int n = mat.length; int...

Continue reading

## Interview Program – Array

Find the length of unsorted subarray such that sorting this subarray can sort all the array. Print the start and end index. public class Solution { public static void unsortedArrayIndex(int ar[]) { int i = 0; int...

Continue reading

## Interview Question – Stack

Given a stack containing n elements reverse the stack with the help of an empty stack. import java.util.Stack; public class StackReversal { public static void reverseStack(Stack<Integer> stack) { if...

Continue reading

## Program to find the number of occurrences in a given String

Problem Statement: Given 2 String source and target, find the number of occurrences that the String target is present in String source and return the count. Test Cases: public static void main(String[] args)...

Continue reading

## Sort the characters Ascending/Descending in a given String

Problem Statement: Given a String, Sort the characters in Ascending/Descending from a given String and return the String Test Cases public class SortCharactersInWord { public static void main(String[] args)...

Continue reading

## Java 60+ Patterns Programs – Stars/Alphabets/Numbers

Following are the Patterns asked in many job interviews for both Freshers as well as Experience. Same logic will apply to all the programming languages. Write a Program to Print the following Pattern import...

Continue reading

## Sort the array elements in Ascending/Descending order using Bubble Sort

Hi guys, Bushan here, welcome back to B2 Tech. Today in this article we will discussing  about one of the most important sorting technique and also an important Java interview program of all time. Given an integer array, sort...

Continue reading