How to print only distinct integer values once even though they are repeated multiple times-CodePudding

I am trying to print only distinct integer values once even though they are repeated multiple times in an array with the introduced order. Firstly, I need to take array size from user but I cannot determine how to initialize that variable.Can I use n -inclueded in the code- as an array size variable? When I compiled I doesn't print anything. Where are my mistakes, and how to deal with them? Any idea?

public static void uniqueNumbers(int arr[], int n)
    {
        for (int i=0; i<n; i  )
        {
            for (int j =0; j<i;j  )
            {
                if (arr [i]==arr[j])
                    break;
            
            if (i==j)
                System.out.print(arr[i]   " ");
                
        }
    }
}

public static void main(String[] args) {
    Scanner sc =new Scanner(System.in);
    int n =sc.nextInt();
    int arr [] = new int [n];
    uniqueNumbers(arr,n);

}

}

CodePudding user response：

You need to fill the array,that is, you need to take input for the array elements.

public static void main(String[] args) {
Scanner sc =new Scanner(System.in);
int n =sc.nextInt();
int arr [] = new int [n];
 //Add the following lines.
for (int i = 0; i < n; i  ) {
    arr[i] = sc.nextInt();
}
uniqueNumbers(arr,n);
}

Print the array and try your logic again.

CodePudding user response：

you need to first request for the size of the array as shown below:


  public static void main (String[] args)
    {
        Scanner scan = new Scanner(System.in);

        System.out.println("Enter array size");

        int n =scan.nextInt();

        // declaring and creating array objects
        int[] arr = new int[n];

        // displaying default values
        System.out.println("Default values of array:");
        for (int i=0; i < arr.length; i  ) {
            System.out.print(arr[i] "\t");
        }

        // initializing array
        System.out.println("\n\n***Initializing Array***");
        System.out.println("Enter "  arr.length
                  " integer values:");

        for(int i=0; i < arr.length; i  ) {
            // read input
            arr[i] = scan.nextInt();
        }


        uniqueNumbers(arr, n);

    }

CodePudding user response：

public static void uniqueNumbers(int[] arr, int n) {
        int slow = 1;
        for (int fast = 1; fast < n; fast  ) {
            if (arr[fast] != arr[slow - 1]) {
                arr[slow  ] = arr[fast];
            }
        }
        arr = Arrays.copyOf(arr, slow);
        for (int i = 0; i < arr.length; i  ) {
            System.out.println(arr[i]);
        }
    }