Delete repeated data in C++

#include <iostream>
using namespace std;
int main()
{
    int a[]={1,2,2,1,3,4,5,3,3};
    for(int i=0;i<10;i++)
    {
        bool equal=false;
        for(int j=i-1;j>=0;j--)
        {
            if(a[i]==a[j])
            {
                equal=true;
            }
        }
        if(!equal)
        {
            cout<<a[i]<<endl;
        }
    }
}