Question

CS 209 Data Structure

1. Create a method that takes an ArrayList of Integer and returns a sorted copy of that ArrayList with no duplicates.

Sample Input: {5, 7, 4, 6, 5, 6, 9, 7}

Sample Output: {4, 5, 6, 7, 9}

Answer 1

Implementation in JAVA;

I have tried to explain through several methods:

or I implemented sorting and removing duplicates from ArrayList through Several Methods

just have a look on whole code:

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

public class Remove_Duplicate_and_sort_list {

  
  
//   will sort elements in list by using Bubble sort
   public static ArrayList<Integer> sort(ArrayList<Integer> list){
      
       for (int i = 0; i < list.size(); i++) {

       for (int j = list.size() - 1; j > i; j--) {
       if (list.get(i) > list.get(j)) {

       int tmp = list.get(i);
       list.set(i,list.get(j));
       list.set(j,tmp);

       }

       }

       }
      
       return list;
   }
  
  
//   this is easiest method to sort a list by using collections
   public static ArrayList<Integer> sort_directlt(ArrayList<Integer> list){
      
       Collections.sort(list);
      
       return list;
   }
  
  
  
//   this method is valid for remove duplicates from sorted lists only
   public static ArrayList<Integer> removeduplicates(ArrayList<Integer> list){
      
   for(int i=1;i<list.size();i++) {
           if(list.get(i)==list.get(i-1)) {
               list.remove(i-1);
           }
       }
      
       return list;
      
   }
  

  
//   very easiest method to remove duplicates from arrayList by using Set
   public static ArrayList<Integer> removeduplicates_directly(ArrayList<Integer> list){
      
       Set<Integer> hashsetList = new HashSet<Integer>(list);
      
       return (ArrayList<Integer>) hashsetList;
      
   }
  
  
//   one another method for removing duplicates and will valid for sorted and unsorted all lists
   public static ArrayList<Integer> removeduplicates_method2(ArrayList<Integer> al){
      
       for(int i=0;i<al.size();i++){
             
           for(int j=i+1;j<al.size();j++){
           if(al.get(i).equals(al.get(j))){
           al.remove(j);
           j--;
           }
           }
             
           }
      
       return al;
      
   }
  
//   driver method and main method
public static void main(String[] args) {
      
   ArrayList<Integer> list = new ArrayList<Integer> ();
     
   list.add(5);
   list.add(7);
   list.add(4);
   list.add(6);
   list.add(5);
   list.add(6);
   list.add(9);
   list.add(7);
     
   System.out.println("The input list is : "+list);
     
   list=sort(list);
   list=removeduplicates(list);
     
   System.out.println("After sorting and remove Duplicates list is : "+list);
      
}
  
  

}

SAMPLE OUTPUT:

If you have any doubt regarding this question please ask me in comments

// THANK YOU:-)