Basic C++ problems

This works fine. Unless I misunderstood your problem.

You can replace vector with an array if you haven't learned it yet.

Code:

#include <iostream>
#include <vector>

/*
"Consider this data sequence: "3 11 5 5 5 2 4 6 6 7 3 -8".
Any value that is the same as the immediately preceding value is considered a CONSECUTIVE DUPLICATE.
In this example, there are three such consecutive duplicates: the 2nd and 3rd 5s and the second 6.
Note that the last 3 is not a consecutive duplicate because it was preceded by a 7.
*/

int main() {
    std::vector<int> holder;
    size_t total = 0;
    int a = 0;
    while(std::cin >> a) {
        holder.push_back(a);
        if(a < 0)
            break;
    }
    for(size_t i = 1; i < holder.size(); ++i) {
        if(holder[i] == holder[i-1])
            ++total;
    }
    std::cout << "Total consecutives: " << total;
    std::cin.get();
    std::cin.get();
}