write a program to print all unique elements in an array

1//write a program to print all unique elements in an array in c
2
3#include <stdio.h>
4
5int main(int argc, char const *argv[])
6{
7    int arr[] = {4, 256, 2, 256, 4, 3, 3, 5}, seen;
8    int arr_length = sizeof(arr) / sizeof(int);
9
10    for (int i = 0; i < arr_length; i++)
11    {
12
13        seen = 0;
14        for (int j = i + 1; j < arr_length; j++)
15        {
16            if (arr[i] == arr[j])
17            {
18                seen = 1;
19            }
20        }
21        if (seen == 0)
22        {
23            printf("%d ", arr[i]);
24        }
25    }
26
27    return 0;
28}
29