8.4

#include <vector>
#include <iostream>
using namespace std;


bool rep(const vector< int> & a, const int &lenght)
{
    bool rep = 0;
    for (int i = 0; i < lenght; i++)
    {
        int count = 0;
        for (int j = i; j < lenght; j++)
        {
            if (a[i] == a[j])
            {
                count++;
                if (count == 2)
                    rep = 1;
            }
        }
    }
    return rep;
}
int main()
{
vector<int> array = { 6, 9,66,785,632,569,56,654,2,0, 31,23,33};
cout <<"Задание 8: "<< rep(array,array.size()) << endl;
}