Skip Dublicate Integers - c++

Question

I'm trying to create a program that would ask the person to write 10 integers, the program should print out the integers that has not already been written, meaning it skips the duplicate integers. I know that I'm supposed to have another for loop but how am I supposed to write it?
If I would write "10, 5, 6, 5, 9, 5" it would print out "10, 5, 6, 9"
This is my current code.
int main()
{
const int target = 10;
int num[target];
cout << "Write " << target << " integers by space: ";
for (size_t i = 0; i < target; i++)
{
cin >> num[i];
cout << "[" << num[i] << "]"
<< " ";
}
};
The output is the same as the input. It never skips the same duplicate.
Some people tell me to use a nested for loop and have something like this, but I don't know how to implement it.
for (int i = 0; i < num.size(); i++) {
if (i > 0 && num[i - 1] == num[i]);
cout << num [I] << " ";
}

Answer 1

The easy way to do it is use both a std::unordered_set and a std::vector. The unordered_set can be used as the logic for determining whether the input is unique. If it is just add it to your vector.
A short example (with minimal input error handling) would be:
#include <iostream>
#include <unordered_set>
#include <vector>
#include <limits>
int main (void) {
std::vector<int> vi{}; /* vector of int to preserve order */
std::unordered_set<int> us{}; /* set for ensuring only unique ints */
int i = 0, n = 5;
std::cout << "enter " << n << " integers\n";
while (i < n) {
int tmp;
std::cout << " " << i+1 << ") "; /* prompt for input */
if (std::cin >> tmp) { /* validate EVERY input */
if (us.find(tmp) == us.end()) { /* if tmp not in set */
us.insert(tmp); /* insert tmp in set */
vi.push_back(tmp); /* insert tmp in vector */
}
i++; /* only increment on good input */
}
else { /* handle error */
std::cerr << " error: invalid\n"; /* display error */
std::cin.clear(); /* clear stream state */
/* clear all characters to end of line */
std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
}
}
std::cout << "\nunique integers\n";
for (const auto& v : vi)
std::cout << " " << v;
std::cout << '\n';
}
Example Use/Output
$ ./bin/vector_unique_int
enter 5 integers
1) 2
2) bananas
error: invalid
2) 4
3) 5
4) 2
5) 4
unique integers
2 4 5
Look things over and let me know if you have questions.

Answer 2

I managed to solve it by using bool. I still don't know how I would write it in another way, please if there is provide me with another solution.
int main()
{
const int target = 10;
int num[target];
cout << "Write " << target << " integers by space: ";
for (int i = 0; i < target; i++)
{
cin >> num[i];
bool unique = true;
for (int j = 0; j < i; j++)
if (num[j] == num[i])
{
unique = false;
break;
}
if (unique)
cout << "[" << num[i] << "]"
<< " ";
}
return 0;
}
Output Was :
Write 10 integers by space: 10 5 10 3 2 5 1 10 9
[10] [5] [3] [2] [1] [9]