CODEWITHSUNDEEP
c++sorting
e3c
e3c

Reputation: 13

Best way to remove non uniques values from an array, keep the order, and not use vectors?

I apologize if this has been asked, but I ran into a coding question, which was supposed to be simple but I struggled on. Please provide a link if already answered (I may just be bad at searching).

Question: Given the sample code fill in the function to return only unique values in the array. Values must keep order.

Example Input : 1, 2, 3, 10, 4, 3, 2, 10, 1, 11, 6

Example Output: 1 2 3 10 4 11 6

Below is my solution, but I can not seem to think of an easy solution that does not include the use of a vector to store unique values. The tester did not like the use of a vector so I can only assume additional headers / libraries were unacceptable. Any other solutions? I am guessing the tester was looking for the array to be filtered in place.

#include <iostream>
#include <vector> //I was not allowed to add this...

//Function to fill in...
int fxn(int *a, int size)
{
  std::vector<int> temp;
  for(int i(0); i < size; ++i)
  {
    bool found(false);
    for(auto j : temp)
    {
      if( j == a[i])
      {
        found = true;
        break;
      }
    }

    if(!found)
    {
      temp.push_back(a[i]);
    }
  }

  int *ptr_a = &a[0];
  for(auto j : temp)
  {
    *ptr_a = j;
    ++ptr_a;
  }

  return size - temp.size();
}

//The rest untochable...
void print(int *a, int size)
{
  for(int i(0); i < size; ++i)
  {
    std::cout << a[i] << " ";
  }

  std::cout << std::endl;
}

int main(void)
{

  int a[] = { 1, 2, 3, 10, 4, 3, 2, 10, 1, 11, 6 };
  int size = 11;

  int count = fxn(a, size);
  print(a, size - count);

  return 0;
}

Upvotes: 1

Views: 80

Answers (1)

arc-menace
arc-menace

Reputation: 475

Admittedly, this problem would be easier if you could use external libraries, but if you are certain you cannot, it is still solvable.

I read the question incorrectly the first time. Here is a link to as similar question.

#include<iostream>
using namespace std;

int removeDuplicates(int arr[], int n)
{
    int j = 0;

    for (int i=0; i < n; i++){
        for(int j=0;j<i;j++){

            if(arr[i]==arr[j]){
                n--;
                for (int k=i; k<n; k++){
                    arr[k]=arr[k+1];
                }
                i--;     // you forgot to decrement i
            }
        }
    }

    return n;
}

Upvotes: 1

Related Questions