Program to print duplicate values of array only once in C++ - c++

Question

int array[5]={3,3,3,3,1,1};
output:
3 1
I am unable to do this, please help me out. I tried 2 for loops with boolean check , it didn't work.
int main()
{
int a[5]={3,3,3,1,1};
int n=sizeof(a)/sizeof(a[0]);
for (int i =0 ; i<n; i++){
bool checked=true;
for (int j=0 ;j<i; j++){
if(a[i]==a[j]){
bool checked=false;
}
}
if(checked==true){
cout<<a[i]<<",";
}
}
}

Answer 1

I used a function to remove duplicate values from the array and then printed the array without the duplicates. I don't have boolean functions.
int removeDuplicate (int arr[], int size) {
if (size == 0 || size == 1) {
return size;
}
int* temp = new int[size]; /* Create a temporary
array with size*/
int j = 0;
for (int i = 0; i < size - 1; i++) {
if (arr[i] != arr[i + 1]) {
temp[j++] = arr[i]; //strore element if its unique
}
}
temp[j++] = arr[size - 1];
for (int i = 0; i < j; i++) {
arr[i] = temp[i]; //modify the existing array
}
return j; //j is the new size for the array without duplicates
}
int main(){
int arr[5] = {3,3,3,1,1};
int size = removeDuplicate(arr, 5);
for (int i = 0; i < size; i++) {
cout << arr[i] << " ; ";
}
}

Answer 2

Please note bool checked=false; you are defining again checked variable.
Please see the fix.
int main()
{
int a[5]={3,3,3,1,1};
int n=sizeof(a)/sizeof(a[0]);
for (int i =0 ; i<n; i++)
{
bool checked=true;
for (int j=i+1 ;j<n; j++)
{
if(a[i] == a[j])
{
checked=false;
}
}
if(checked == true)
{
std::cout<<a[i]<<",";
}
}
}
output : 3,1,
Even you can do it in a better way with std::unique algorithm.
#include <iostream> // std::cout
#include <algorithm> // std::unique, std::distance
#include <vector> // std::vector
int main () {
int a[5]={3,3,3,1,1}; // 3 3 3 1 1
std::vector<int> myvector (a, a+5);
// Sorting the array
std::sort(myvector.begin(), myvector.end());
// using default comparison:
auto it = std::unique (myvector.begin(), myvector.end());
myvector.resize( std::distance(myvector.begin(), it));
// print out content:
std::cout << "myvector contains:";
for (it=myvector.begin(); it!=myvector.end(); ++it)
std::cout << ' ' << *it;
std::cout << '\n';
return 0;
}
output : myvector contains: 3 1