How to print unique numbers in Array.

[nyaonyao]

so my program is supposed to use one 5 sized array to store inputted integers. If it's a duplicated integer it would not be stored into the array.

The problem here is there would be 0's in my array indefinitely since i initialized the size to 5, there would always be 5 elements regardless if all 5 is being used or not. I need to output only the unique numbers how would i do so?

One thing i noticed was that without my unsigned int position; whenever i enter a duplicate integer it would skip the index;

e.g. array[0] = 10, array[1] = 10 // duplicate, array[2] = 20 // inputted 20, this should've been stored into array[1] but it doesn't. So i had the position to only increment whenever it's not a duplicate to make sure it's not skipping over the index when a duplicate is entered.

So the problem is if say my input was 10 10 20 30 40, my outputted display would be 10 20 30 40 0 because the last index is not used since the 2nd Int 10 input was ignored and not stored into the array but the counter would still increment for the outer loop to prompt the user to enter the next #; instead i want it to be just 10 20 30 40 and not output the 0.

And was there anything i could've done or do a different approach to get my result?

Code:

#include <iostream>
#include <iomanip>
#include <array>

using namespace std;

const unsigned int MIN_VALUE = 10;
const unsigned int MAX_VALUE = 100;
const size_t arraySize = 5;
array <int, arraySize> numberArray = {};

template<size_t size>
bool isDuplicate(array<int, size> array, int value)
{
    for (unsigned int i = 0; i < array.size(); i++)
    {
        if (value == array[i])
        {
           return true;
        }
    }
    return false;
}

int main()
{

  unsigned int input;
  unsigned int position = 0;

  for (unsigned int i = 0; i < arraySize; i++)
  {
      cout << "Enter # " << (i + 1) << " : ";
      cin >> input;

     if (input < MIN_VALUE || input > MAX_VALUE)
     {
        cout << "The number entered is not in valid range of 10 to 100" << endl;
        --i;
     }
     else if (!isDuplicate(numberArray, input))
     {
         numberArray[position] = input;
         position++;
         cout << "The number: " << input << " is unique\n" << endl;
     } 
   }
} 

Thanks!

[Duthomhas]

Ah ha! You have discovered one of the important parts of handling arrays: arrays have N elements, but you may only need to use n elements.

C++ literature tends to use the words 'capacity' for the total size of the array, and 'used' for the number of elements used in the array.

You must keep track of both.

  int anArray[arraySize] = {0};
  int arrayUsed = 0;

  if (arrayUsed < arraySize) anArray[arrayUsed++] = 7;
  if (arrayUsed < arraySize) anArray[arrayUsed++] = 94;
  ...

  for (int n = 0; n < arrayUsed; n++)
    cout << anArray[n] << "\n";

Hope this helps.

[nyaonyao]

Hmm yeah, except the part where you have the if statements and then assigning 7 to it? are u assigning the array size? i don't really get that part of the code.

Thanks!

[nyaonyao]

Hi,

Don't really get the code at the if statement so your checking the arrayUsed if its < than the array size? if it is increment the array size and then assigned 7 to it? what does that do?

Thanks!

[Duthomhas]

7 and 94 are just random numbers. The whole point is to show how to add an element to then end of the array, but only if there is room.

[nyaonyao]

Ahhh okay, thanks a lot!