**1) Fibonacci in Java:**

**The input will be number n and the output should be sum for 0 to n. for example**

for n =4 the result should be 0+1+2+3+4 = 10

*2) String*Reverse
The input String "abcde" should return "edcba".

**3) Reversing a linked list in Java**

Here is example of revering the linked list in java using recursive function:

**4) Find the missing number in Java**

You have an array of numbers from 1 to 100 (both inclusive). The size of the array is 100. The numbers are randomly added to the array, but there is one random empty slot in the array. What is the quickest way to find that slot as well as the number that should be put in the slot?

Try it for practice. please suggest the answer .

[Trick sum of n numbers is n*(n+1)/2]

**5) Write a substring function in Java**

String test= "AA BB CC BB BB CC BB";

String[]{"BB", "CC", "AA"}

Result shd be BB=4; CC=2 and AA=1

Since B occurred 4 times C did 2 times and A only 1 time.

This basic problem can be asked in different ways like, You have multiple words in new paper and find out the frequency of words in one page of news paper?

**6) Reverse a String in Java**

Reverse the String by java function without recursion and with recursion

**7) Find one string inside another in Java**

We can use String.indexOf( subString ) and it will return the first index of substring;

for Last Index :

**lastIndexOf**(String str)**8) Algo for finding largest number in Array of Integer**

Easy one, Check the integer one by one and find the largest number.

**9) Java Runtime method invocation question:**

*Example : Tell the output of this*

**Answer is : 20 .**

**10) Suppose you have a large file with lots of words. How would you find the unique words and their count? What kind of data structure u will use? What will be the time complexity and space complexity?**

We need to take care of two things counting the words and second duplicate. the best performance will be using hash function.

**11) A train is one mile long. It travels at the rate of one mile a minute through a tunnel which is also one mile long.**

**Can you say how long it will take for the train to pass completely through the tunnel?**

**Answer : 2 minutes**

it will take two minutes if you count the time for it to completely pass through the tunnel. One minute to pass through the tunnel and another one minute to drag itself out of the tunnel completely so two minutes nice question though well logical.

**12)**

**Convert String = "98989" into an integer without using any library functions in java.**

**Give fastest way to do it and explain why your method is best.**

// converting string to number using ascii code

**13) Write a program to shuffle a deck of 52 cards and shuffle them equally to 4 players.**

**Answer this puzzle by comments.**

**Given n stairs, how many number of ways can you climb if u use either 1 or 2 at a time?**

for example you have 4 stairs and you can climb like

1,1,1,1

1,1,2

1,2,1

2,1,1

2,2

so in overall 5 ways for 3 stairs.

nice blog thanks company jobs

ReplyDeleteThe problem statement of "4) Find the missing number" is vague, could you please refine / clarify it?

ReplyDeleteIn Java 1.6 uses the Generics.....to put like this

DeleteSet numberSet = new HashSet();

In java using the generics

Deletepackage com.bangalore;

import java.util.HashSet;

import java.util.Random;

import java.util.Set;

public class MissingNumber {

public static void main(String...strings){

Set num = new HashSet();

// Max number in the sequence

int k = 50;

// put the numbers

for(int i=0;i<=50;i++){

num.add(i);

}

// Remove random number

int i = (new Random()).nextInt(50);

System.out.println(" Removing number -->"+i);

num.remove(i);

// find the current sum

int sum =0;

for(int m : num){

sum= sum +m;

}

// Find the missing number

int l = ((k)*((k+1))/2)- sum;

System.out.println(" Missing number -->"+l);

}

}

The first example seems different from fibonacci series. If It is 0+1+2+3+4 +.. n

ReplyDeleteShouldnt it be

private static int getSeriesResut(int n) {

int sum = 0;

for (int i = 1; i <= n; i++) {

sum = sum + i;

}

return sum;

}

This comment has been removed by the author.

ReplyDeleteThis comment has been removed by the author.

DeleteFor Fibonacci Series ... using iteration seems to be much more performant than recursion.

ReplyDeleteBoth methods are compared here: https://gist.github.com/josseyj/9062009

very nice. for java examples, visit http://java2novice.com site

ReplyDeletethe card suffling example will give the same result every time you run it as you are neither suffling the deck nor using the temp variable.

ReplyDeleteadding Collections.shuffle(deck) would sufficce for your example

Very Intresting Blog...

ReplyDeleteSEO packages San Francisco