ALGORITHM TO DETERMINE STRING CONTAINS UNIQUE CHARACTER

Implement an algorithm to determine if a string has all unique characters. With and without using extra additional data structures

/**

* Implement an algorithm to determine if a string has all unique characters.

* With and without using extra additional data structures?

*

@author Sonu Mishra

*/

public class StringContainsUniqueCharacter {

/**

* Without using extra DS.

*  Ignoring int variable. Time complexity is

* O(n), where n is the length of the string, and space complexity is O(n).

* We can reduce our space usage a little bit by using a bit vector.We will

* assume, in the below code, that the string is only lower case ‘a’ through

* ‘z’.This will allow us to use just a single int

*

@param str: String to check

@return : true/false

*/

Not Accessible Due To Restriction On Required Library

Not Accessible Due To Restriction On Required Library

Today, I was working on some java project in my favourite Eclipse editor, when I encountered some unknown problem. It was throwing some error that the calss cannot be accessed due to restriction on required library. This type of error occurs when some classes cannot be loaded into the projects since some restriction rules are being imposed on those classes. Similarly, I got the error like this:

How To solve this Exception:

As this error is coming because of some setting where we are excluding some files. So we need to change that settings. For that, click on the 'Windows' --> 'Preference' and then go to 'Java'-->Compiler-->'Error/Warnings' tab. You will find 'Forbidden reference (access rules):' and its value has been set to 'Error'. So we only need to do is, to change the 'Error' to 'Warning', and all is done.

Swapping the Variables Without Using Third Variables

Swapping the Variables Without Using Third Variables Using Java

In this post, we will see, how to swap the variables. There are different ways to swap the variables. The major swap algorithms are:
1) Swapping using the third varaibles.
2) Swapping using the Bitwise Operator. This is only for the Integer. This doesn't use the third variables.
3) Swapping using the Arithmetic Operations. This is also, only for the Integer. This also, doesn't use the
    third variables.
4) Swapping the Strings without using the third variables. This is little bit tricky. The logic is similar to the
    above one, i.e. Arithmetic Operations. But the Strings are immutable in the Java, so, externally we are not
    using the third variables, but internally, this uses the third variables.

Below, we have the Java Program to discuss all the above methods in details.

/**
* This class will reverse the two variables.
* Here we will see how to swap the variables using or without using the third variables.
* @author Sonu Mishra
*/
public class SwapVariables {
/**
* Swapping using the third variable and without the third variables.
* Swap two variables using the temporary variables or the third variable.
* @param a The first variable.
* @param b The Second variable.
*/