Count Duplicate String In Array Java

Write a program to count the occurrences of an element in an array is one of the basic question which will be asked in a Java Interview. In Java 8, we can make use of streams to count distinct elements present in the array. Java Program to Count Number of Words in Given String; Java Program to Count the Number of Occurrences of Substring in a String; Java Program to Count the Occurrences of Each Character in String; Java Program to Merge two String Arrays ; Java Program to Remove Duplicate Words from String ; Java Program to Reverse a String(5 ways) Java Program. Whether a character is normal is determined by a 26-digit bit string named charValue. In case of duplicates the function doesn’t produce some results. concat method is static and count, sorted and distinct methods are called on stream object created by stream() method calling on collection. However, if performance is not a critical issue, or you have already split the sentence in order to perform other types of queries over it, then it makes sense to use LINQ to count the words or phrases as well. I have an array of strings, some of which are duplicates. import java. Note that binary search in an array is basically the same as doing a lookup in a perfectly balanced binary-search tree (the root of a balanced BST is the middle value). We loop through the array comparing whether the current smallest number is bigger than the array value. Previous Next In this post, we will see how to remove duplicate elements from ArrayList in java. The idea is to insert all elements of the array into a HashSet. util package. C Program to Find Smallest Element in Array in C Programming; C Program to Calculate Addition of All Elements in Array; C Program to Delete duplicate elements from an array; C Program to Read integers into an array and Reversing them using Pointers; C Program to Implement Stack Operations Using Array; C Program for binary search on array using. retainAll(s2). Python & JAVA Solutions for Leetcode. 3) No of occurrence of all item in the list using HashMap. When we use literal strings in Java, we use the quote (") character to indicate the beginning and ending of a string. The declaration consists of two parts. Java Program to Insert Element in Array. I need to remove the duplications and end up with an array that has one instance of each unique string. Find duplicate element from an array in Java || Find duplicate elements in array in java. I have already created the array and limited the values to numbers ranging from 1-6, but the only method in my book I see is an example of counting the occurrence of each letter in an array, but I am not sure how to modify it to count numbers. In fact, the array's history goes back so far that most languages (including Java) have special notation for dealing with arrays. First, you're checking for duplicated characters within a string, NOT if there are duplicate strings within an array of strings. The worst-case time for binary search is proportional to log 2 N: the number of times N can be divided in half before there is nothing left. Each field and method has an access level: private: accessible only in this class (package): accessible only in this package protected: accessible only in this package and in all subclasses of this class. Pseudo code/Logic for Count occurrences of Character in String in Java I will use HashMap to count occurrences of Character in String in java. A character is special if its value is 1 and normal if its value is 0. Each room is of the same size and. please help! My assignment has the following criteria: Using a linear search determine how many of each number was input. But this time, we are calling the Print Array elements method Recursively with updated values. Sort String in Java. Well, so good so far, it's time to check the basic of java and basic of algorithm to find number of occurrence of all numbers from int array. Also understand Pass by reference and Multidimensional arrays. please help! My assignment has the following criteria: Using a linear search determine how many of each number was input. Each field and method has an access level: private: accessible only in this class (package): accessible only in this package protected: accessible only in this package and in all subclasses of this class. Java String replace(): The Java String replace() method returns a string, replacing all the old characters or CharSequence to new characters. 2 A few main points about arrays in Java: 3 Why using Arrays 4 Example of Java int array 5 An example of a string array 6 An example of […]. Step by step descriptive logic to count duplicate elements in array. How to Convert an Array to String in Java [Snippet] - DZone Java Java Zone. Remove duplicates from an array java This is the java programming blog on "OOPS Concepts" , servlets jsp freshers and 1, 2,3 years expirieance java interview questions on java with explanation for interview examination. nth works on Java Strings, Lists and arrays. String in Java is immutable. Each is examined here. #8 String to Integer (atoi) Medium #9 Palindrome Number. This guide demonstrates finding duplicate string using RhinoScript. Array values can be accessed by position, with strong typing (the result is a primitive or SObject value of the Array member type). You may also like - Find largest and smallest number in the given Array Find duplicate elements in an Array find common elements between two Arrays. It will have Character as key and its count occurrences as value. Since there are n values from 1 to n-1 with one duplicate, we can use the fact that the sum of the integers from 1 to m is (m*(m+1))/2, take the sum from 1 to n-1, subtract that from the actual sum of numbers in the array, and the result will be the duplicated. Search for it's duplicate element from index i+1 to N-1. Pseudo code/Logic for Count occurrences of Character in String in Java I will use HashMap to count occurrences of Character in String in java. Java Forums on Bytes. 1- You can use a HashMap to find duplicate characters in a String along with repetition count. But this time, we are calling the Print Array elements method Recursively with updated values. Find duplicate elements in ArrayList - This example will show, how to find no of duplicate item occurrence from a ArrayList. Array is a fundamental construct in Java that allows you to store and access large number of values conveniently. Java Examples: Strings - Count Unique Characters In A String. net framework. Hence LinkedHashSet is the best option available as this do not allows duplicates as well it preserves the insertion order. Split method is newer method in java, StringTokenizer was old method and previous …. Using String. Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length. Find duplicate elements in ArrayList; Creating Custom Generator class in Hibernate; CRUD Operations Using Hibernate; Creating our Own Hibernate Template class; Caused by: java. In this java program, we have an array with combinations of strings and integers, and program will count total number of strings are integers. Question: Part 2: Fill-in Find Duplicate Count. Do you need to retain that functionality? The hash table solution I provided won't do that, it will just report which ones had duplicates, but not where in the input they are. In this java program, we are going to read an array and removing the duplicate elements from it. 2 A few main points about arrays in Java: 3 Why using Arrays 4 Example of Java int array 5 An example of a string array 6 An example of …. That’s all for the topic Java Program to Find Longest Palindrome in The Given String. Here are a few examples showing how to work with Java arrays, including a Java int array, and a Java String array. String in Java is immutable. if we achieve those 2 things then we will get the result as you expected. Java Program to Insert Element in Array. Here is the relevant code:. Although the characters that comprise a string within a String object cannot be indexed as if they were a character array, many of the String methods employ an index (or offset) into the string for their operation. The most efficient process for traversing the elements of a String type array in java is using loops. The type of an array has a data type that determines the types of the elements within an array (int, String, float in our case) and a pair of square brackets []. Random Integer Set Generator. Then we extract a Set containing all keys of this HashMap using. Therefore a new String is created out of this array and its substring()method is called to remove the trailing duplicate characters using the updated length. Let see how we can count the occurrence using HashMap. The compiler is optimizing bounds-checking in the loop body. Count > 1 For Each item In q ' item with duplicate Console. Let’s tweak in : Method 1 and 2 have much better complexity as compared to Method 3. How to find duplicate elements in int array? There are various approaches to find duplicate elements in the array as given below. String array or integer array or array of any object. The user will enter the string and the program will find the count of each word and print out the result. Java: Generate the alphabet in random order, no duplicates The number array is filled with -1s at the beginning, but as the for loop progresses, the number array gets filled up with numbers. Write a program to implement hashcode and equals. To concatenate Lists, Sets and Arrays we will convert them into stream first and using concat() we will combine them. This is one of the interview question which generally can asked in … Continue reading How to count occurrence of int in array in java →. Imagine you have an array of strings which contains duplicates. In the above code, we are taking in an array of values, string or integer is fine. java that takes integers M, N, and T as command-line arguments, then uses the code given in the text to perform T trials of the following experiment: Generate N random int values between 0 and M–1 and count the number of distinct values generated. Java Program to remove duplicate element in an Array. java,class,hex I understand the structure of a java. Method 2: Anagram Program in Java without using Array. println() (1) Java Example Programs interview (1) Java Interview programs on Strings (1) Java Object Oriented (1). Quick Reach 1 What is Java array? 2 How to declare an array 2. I have faced this question for the java developer position twice. In above example, we get a Java program to count how many times a word appears in a String or find duplicate words. This method will not suit you if you want partial copy of the array. Duplicate is defined as two or more identical elements. How to remove duplicates from list : Here I am creating a Department class, it holds department details. search example. How to remove duplicates from list : Here I am creating a Department class, it holds department details. That is, Object[] is a supertype of String[] for example. I display only distinct values in a listbox (that is working just fine), but I cannot figure out how to the number of times the item was found in the array. Only the constraints is to the solution should satisfy O(N) complexity. ie, 256 ASCII characters, count=0 for each character 2. int main() {. In the above code, we are taking in an array of values, string or integer is fine. anyDuplicated() : an integer or real vector of length one with value the 1-based index of the first duplicate if any, otherwise 0. C++ Program to Find Duplicate Elements in Array. To concatenate Lists, Sets and Arrays we will convert them into stream first and using concat() we will combine them. What i mean is say for example "Employee" class has a property "empName" and i do. C# Corner Annual Conference 2020 Tickets on Sale Now x Learn Flutter Programming. You have already seen one example of Java arrays repeated quite a few times. Traversing a String Array in Java. For more control over the split use the StrTokenizer class. In this tutorial, I'll show how to declare, populate, and iterate through Java string arrays, including the newer for-loop syntax that was introduced with Java 5. In this post we'll see a Java program to find duplicate characters in a String along with repetition count of the duplicates. Let's discuss these thing with example so we are writing java program with main method which contain an ArrayList with duplicate items. To demonstrate, consider the following array, which holds the numbers 1 through 10:. The inner loop will be used to compare the selected element with the rest of the elements of the array. There are two way to copy one sting into another string in C++ programming language, first using pre-defined library function strcpy() and other is without using any library function. Find duplicate element from an array in Java || Find duplicate elements in array in java. Each is examined here. But to do so, you would need access to a computer with the Java platform installed on it — the Java platform is the basic prerequisite for running and developing Java code, thus it is divided into two essential pieces of software: the Java Runtime Environment (JRE), which is needed to run Java applications and applets;. For example, in the array [1, 2, 2, 3, 3, 3], the two twos are one duplicate and so are the three threes. This can be a Java program to find unique words in a string, also. Write a program to implement hashcode and equals. Remove duplicate characters in a given string keeping only the first occurrences. Java Code:. What is an Array? An array is a very common type of data structure wherein all elements must be of the same data type. How to find and remove duplicates in a Array / ArrayList 2. This simplified java program getting an array of the input string and remove the duplicate from the array and return the array unique elements. The array is a venerable, tried-and-true feature of many programming languages, including newer languages such as Java and older languages such as FORTRAN. Note that binary search in an array is basically the same as doing a lookup in a perfectly balanced binary-search tree (the root of a balanced BST is the middle value). For each of the methods with no parameters and a name starting with "get" or "is" followed by an uppercase letter, the method is invoked, and a key and the value returned from the getter method are put into the new JSONObject. Whereas in HashMap store elements in “key/value” pairs, and you can access them by the key. In this tutorial, learn How to Declare, Create, Initialize Array in JAVA with Examples. The return type of the output is the count of all unique characters in the strings. Each field and method has an access level: private: accessible only in this class (package): accessible only in this package protected: accessible only in this package and in all subclasses of this class. The following Java program prints the smallest number in a given array. The SUM function adds all the numbers that you specify as arguments. whether array contains desired number of random numbers or not (to print the final array elements) whether the generated random number is existed in the array previously or not. Let's discuss these thing with example so we are writing java program with main method which contain an ArrayList with duplicate items. For example, you can use counting() to count the number of items, as shown in Listing 11. Java Forums on Bytes. Use Collection framework to sort the List using a comparator. Returns the number of duplicate values it works with arrays of any type, except objects The array is not REDIMed, but you can do it easily using the following code: a() is a string array. The second part defines how many iterations you want to make in the for loop. File Difference tool will help you to compare text files, XML, JSON, Code, String, binary files. Previous Next We can remove duplicate items from ArrayList in java by simply converting ArrayList into Set in Java. You have already seen one example of Java arrays repeated quite a few times. C# Corner Annual Conference 2020 Tickets on Sale Now x Learn Flutter Programming. Next, we are using For Loop to iterate each element in this array, and print those array elements. ; Various ways to remove duplicate elements from Arrays: Read More. We need a data structure to keep track of the characters we have seen so far, which can perform efficient find operation. You can count the number of duplicate elements in a list by adding all the elements of the list and storing it in a hashset, once that is done, all you need to know is get the difference in the size of the hashset and the list. So all the techniques you learn by solving array-based coding questions can be used to solve string programming questions as well. Given an array of intergers, and need to count the number of duplicate array elements. Understand what it means to find the length of a string. Returns the number of duplicate values it works with arrays of any type, except objects The array is not REDIMed, but you can do it easily using the following code: a() is a string array. Quickly finding duplicates in an ArrayList. Needed solution for this problem in java Given a string say s and k denotes the number of commas and the output should be like when you insert the comma in the string at different places and find the maximum number. Also, the Java program will find the repeating words in the string. Java program to insert an element in an array or at a specified position. Here is different ways of java 8 stream group by count with examples like grouping, counting, filtering, summing, averaging, multi-level grouping. Then , we will traverse char array and increment its value by 1 for each. Remove duplicate characters from String in Java December 3, 2018 SJ String Handling 0 In this article, we will discuss steps and execution program to delete/remove all duplicate characters/occurrences from given String. String Arrays. However, if A is a string scalar, numel returns 1 because it is a single element of a string array. The countMatches() method of the StringUtils class of the Commons LangS library can be used to count the number of occurrences of a String in another String. First, we convert the given string to char array. If array is not sorted, you can sort it by calling Arrays. Java String array FAQ: Can you share some Java array examples, specifically some String array examples, as well as the Java 5 for loop syntax?. An additional integer array will be used to store the number of duplicates of each word. Finally, this array is copied to a new array with its length equal to the number of unique elements in the original array (that is, value of size) using copyOfmethod of java. Example 1: Grouping by + Counting. The example also shows how to count duplicate elements in various ways. Solution and logic shown in this article are generic and applies to an array of any type e. Although we can find arrays in most modern programming languages, Java arrays have some unique features. We are then creating an empty associative array which will store the counts of each array element. Scan the input string and construct a character count array from input string ie, In the above example, count of t is 2, so count['t'] = 2 count of u is 2, so count['u'] = 2 count of o is 1, so count['o'] = 1. Just check the count which will be equal to one for unique words. Note that to perform the count, first the Split method is called to create an array of words. C++ Program to Copy One String into Another String. In fact, the array's history goes back so far that most languages (including Java) have special notation for dealing with arrays. The worst-case time for binary search is proportional to log 2 N: the number of times N can be divided in half before there is nothing left. NET, the demo project at the link below is easy. This example uses an inline array, however it can be easily changed to a method taking an array as parameter. Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct. Random Integer Set Generator. Group Console. net framework. The user will enter the string and the program will find the count of each word and print out the result. An array of integers named parkingTickets has been declared and initialized to the number of parking tickets given out by the city police each day since the beginning of the current year. Python & JAVA Solutions for Leetcode. Removing duplicate objects from List collection in java, best way of removing duplicate values from java collection List or ArrayList, [Line number 22] What if i do not want my array list to contain duplicate object based on a particular property. You can use Arrays, which has a method CharArray() that will create a char input string and using another method (Arrays. Input and Output Format: Input consists a string. Sorting an array and removing duplicates can be done in many ways but I will discuss two ways. Java - limit number of duplicate characters in a string. This exercise is covered on page Finding Two Numbers That Appear Once in Array of Duplicated Numbers. Here is source code of the C++ Program to Find Duplicate Elements in an Array. How to count occurrence of int in array in java September 3, 2016 java algorithms , java Ranjeet Jha Well, so good so far, it’s time to check the basic of java and basic of algorithm to find number of occurrence of all numbers from int array. Programming Tutorials 10,150 views. When we are dealing with small number of data, we can use a variable for each data we need to monitor. The time complexity of this solution is O(N 2 ) and space complexity is O(1) as the same string is used and memory requirement in the program doesn’t increase. seq works on Java reference arrays, Iterables and Strings. I need to remove the duplications and end up with an array that has one instance of each unique string. Logic to count duplicate elements in array. Best How To : the problem is the method you are using is not sufficient. You can have an array of integers or an array of strings or an array of arrays, but you can't have an array that contains, for example, both strings and integers. put("stack", "overflow", "stack", "yahoo", "google", "msn", "MSN", "stack", "overflow", "user"); Map. Java program to count number of duplicate words in given string. Write a program to convert binary to decimal number. Example 1: Grouping by + Counting. Java program to count the occurrences of each character; Java program to count the occurrence of each character in a string using Hashmap; How to Become A Successful Java Developer? How to convert an Array to String in Java? Add the given digit to a number stored in a linked list using recursion; How to determine length or size of an Array in Java?. The logic is you'll separate the array into two array, duplicate array and unique array. How to find duplicate words in a line of text 4. Java Program to Insert Element in Array. Increment the count of each character by using ASCII of character as key ie, arr[s[i]]++ here, s[i] gives the ASCII of the present character 3. Though it is written in VB. LeetCode - Contains Duplicate (Java) Given an array of integers, find if the array contains any duplicates. This can result in different numeric indexes. For example if the array contains {1,2,3,2,1,4} then {1,2} duplicate elements and output should be 2. Also understand Pass by reference and Multidimensional arrays. For example, if an array with length 6 contains numbers {0, 3, 1, 2, 3}, then duplicated number is 3. toCharArray(); is used to convert the given string to character array with the name inp using the predefined method toCharArray(). In this post of Java program to Remove Duplicate Elements From an Array We will look into three different methods to remove duplicate elements from an array. We add all elements to LinkedHashSet, and then get back the content in array. An additional integer array will be used to store the number of duplicates of each word. Solution and logic shown in this article are generic and applies to an array of any type e. Each field and method has an access level: private: accessible only in this class (package): accessible only in this package protected: accessible only in this package and in all subclasses of this class. The brackets indicate. Finally, this array is copied to a new array with its length equal to the number of unique elements in the original array (that is, value of size) using copyOfmethod of java. In this post, we take a closer look at duplicate objects in Java and how they not only impact strings but other classes as well, including arrays. The type of an array has a data type that determines the types of the elements within an array (int, String, float in our case) and a pair of square brackets []. The separator is not included in the returned String array. g for string “aaaa” the string “aaa” itself is not generated. Determining a Character's Unicode Block: 25. Java String array is basically an array of objects. Finally, iterate over HashMap keyset and check with each key's value, if it is greater than 1 then it is a duplicate word. Learn how to copy an array in Java, with examples of various methods. This tutorial demonstrates how to convert a list to an array in Java, using different array methods, the Apache Commons Lang, Commons Collection, and Guava. ; Using for-each loop, traverse input array and for each element check whether element exists in Map or not. For finding duplicate values in JavaScript array, you'll make use of the traditional for loops and Array reduce method. Declare a Map to store the frequency of elements of inputArray. To demonstrate, consider the following array, which holds the numbers 1 through 10:. This simplified java program getting an array of the input string and remove the duplicate from the array and return the array unique elements. To count total duplicate elements in given array we need two loops. Oct 14, 2015 Array, Core Java, Examples, Snippet, String comments A Java String Array is an object that holds a fixed number of String values. Java arrays start with an index of 0, so your increment number should always be initialized to 0. Count All The Numbers That Are Repeated In The Array Entries. Count Unique Characters In A String Here is a java example that counts the number of unique characters in a string without using Sets or Maps. We can use a Java array as an array of immutable objects. In given example, numbers is an integer array which has duplicate numbers 1, 3 and 5. replace() method, but for large amounts of data, and high number of replacements, this performs badly. The time complexity of this solution is O(n) because we need to iterate over all element in the array. util), such as Arrays. There are two types of characters in a particular language: special and normal. Douglas McIlroy's "Engineering a Sort Function", Software-Practice and Experience, Vol. Algorithm: 1. Find a duplicate in an array; Given an array of n + 1 integers between 1 and n, find one of the duplicates. C program to delete duplicate elements from an array. Java program to remove duplicates in array using LinkedHashSet. The function should return the index of the first number. As a first step we will be creating a HashMap “countMap” to hold the element (Key) and the count as the value. The statement: char [] inp = str. A field is like a C++ data member, and a method is like a C++ member function. count down: 10 count down: 9 count down: 8 count down: 7 count down: 6 count down: 5 count down: 4 count down: 3 count down: 2 count down: 1 count down: 0 count down: -1 Loops infinitely. public String​(char[] value, int offset, int count) Allocates a new String that contains characters from a subarray of the character array argument. I have an array of strings, some of which are duplicates. LeetCode - Contains Duplicate (Java) Given an array of integers, find if the array contains any duplicates. Java Forums on Bytes. Convert from ASCII code to String: 22. Store it in some variable say size and arr. Traversing a String type array is an extremely simple process. Simple Program to remove Duplicate Element in an Array. Version 2: This version uses a local variable instead of array. 1631 134 Add to List Share. First, we convert the given string to char array. String Deduplication takes advantage of the fact that the char arrays are internal to strings and final, so the JVM can mess around with them. For 8-bit and 16-bit images, returns an array with one entry for each possible value that a pixel can have, from 0 to 255 (8-bit image) or 0-65535 (16-bit image). This method will not suit you if you want partial copy of the array. Many of the Clojure library functions have defined semantics for objects of Java types. WriteLine(item. Though it is written in VB. So if the limit is 1 duplicate, after the first 2 'a' characters, any 'a' character after that should be excluded from the return. If sort_flags is SORT_STRING, formerly array has been copied and non-unique elements have been removed (without packing the array afterwards), but now a new array is built by adding the unique elements. The example also shows how to count duplicate elements in various ways. An array of integers named parkingTickets has been declared and initialized to the number of parking tickets given out by the city police each day since the beginning of the current year. If the distinct count is not same as the length of the array, array contains a duplicate. Below are the four method for removing duplicate entries from an array, all does same task with the different - 2 ways using list contain (internally using linq) method, collection distinct extension method (internally using linq need. Rotate an array of n elements to the right by k steps. Make sure this question in your to do list before appearing for the. Learn how to copy an array in Java, with examples of various methods. The program output is also shown in below. Given an array of integers, your task is to count the number of duplicate array elements. Fill boolean, byte, char,short, int, long, float array; Get array upperbound; Get the number of dimensions; Insert an Element into a Sorted Array; Insert the specified element at the specified position in the array; Insert source array in the target array at offset; Maximum value in an array; Minimum value in an array. Get count array from the second string which stores the count of chars from the second string. we have methods to transform our array into a String for. It will have Character as key and its count occurrences as value. There are two ways to initialize string array - at the time of declaration, populating values after declaration. import java. The length of the array at this point contains the index of the last non-duplicate element. In this tutorials, I am going to show you how to remove duplicate elements from the list using Java 8 syntax. Java program to remove duplicate characters from a String February 27, 2018 0 In this article, we will discuss how to remove duplicate characters from a String. You will use two loops and equals method to compare each word in the array and count the number of duplicates of every word. retainAll(s2). The array is a venerable, tried-and-true feature of many programming languages, including newer languages such as Java and older languages such as FORTRAN. Given string s, return the longest substring of s that contains at most k normal characters. RhinoScript has a method to cull the duplicate strings. Find the count of students. Taverna has a beanshell where I can program in java. LeetCode - Contains Duplicate (Java) Given an array of integers, find if the array contains any duplicates. This example that uses the code from the Scratch solution (you can go to Repeat a string#Scratch for the original example), which requires making variables named "String", "Count", and "Repeated" first, works, unmodified:. To insert element in an array in Java Programming, you have to ask to the user to enter the array size, array elements and ask to the user to enter the element and position where he or she want to insert the element to insert that element at desired position. Count the number of chars included in the given byte[]. Count Repeated Words: Following Java program to counts how many times a word appears in a String or find repeated words. class file, but when I want to interpret the raw hex data I get a bit lost. There is a performance cost to the Split method. How to count duplicate elements of ArrayList September 26, 2016 SJ Collection 0 In this article, we will count of number of duplicate elements present in List using Collections class’s utility frequency() method. The randomness comes from atmospheric noise, which for many purposes is better than the pseudo-random number algorithms typically used in computer programs. Contribute to qiyuangong/leetcode development by creating an account on GitHub. If array is not sorted, you can sort it by calling Arrays. Count all the numbers that are repeated in the array entries. #8 String to Integer (atoi) Medium #9 Palindrome Number. On this page we will provide Java 8 concat Streams, Lists, Sets, Arrays example. Approach: Create a HashMap and character of String will be inserted as key and its count as value. You can make use of ES6 Set to remove duplicate from an array. Traversing a String Array in Java. Improve this sample solution and post your code through Disqus. How to Convert Between List and Array. The program also results the cont of the duplicate characters. Using Arrays in SAS® Programming Arrays provide an alternative method of referring to variables. All items in a Java array need to be of the same type, for instance, an array can't hold an integer and a string at the same time. If sort_flags is SORT_STRING, formerly array has been copied and non-unique elements have been removed (without packing the array afterwards), but now a new array is built by adding the unique elements. How to find duplicate words in a line of text 4. A Java example to show you how to count the total number of duplicated entries in a List, using Collections. This Java program is the same as the above. Write a Program in Java to input a number and check whether it is a Unique Number or not. Use a HashSet in removeDuplicates. To count total duplicate elements in given array we need two loops. For each character, check if it is duplicate of already found characters. Write a program to find perfect number or not. You have a museum with a grid layout for its rooms. Given a string, Write a program to remove duplcate characters from the string. Imagine you have an array of strings which contains duplicates. Let see how we can count the occurrence using HashMap.