dominator of an array

01.dominator.cpp

// 01.dominator.cpp
// juanfc 2018-02-06
#include <iostream>
#include <array>
using namespace std;

const int N = 9;
typedef array<int,N> TVec;

int dominator(TVec a);

int main() {
    TVec a1 = {{3,4,3,2,3,1,3,3,1}},
         a2 = {{4,4,3,2,3,1,3,3,1}},
         a3 = {{1,3,2,1,4,4,4,4,4}};

    cout << "The dominator of a1 is: "
         << dominator(a1) << endl;
    cout << "The dominator of a2 is: "
         << dominator(a2) << endl;
    cout << "The dominator of a3 is: "
         << dominator(a3) << endl;

    return 0;
}


int count(TVec a, int x);

int dominator(TVec a) {
    int i = 0;
    int r = -1;
    int midpoint = a.size()/2;
    while (i <= midpoint and count(a, a[i]) <= N/2)
        ++i;
    if (i <= midpoint)
        r = a[i];
    return r;
}
int count(TVec a, int x)
{
    int cnt = 0;
    for (int i = 0; i < a.size(); ++i)
        if (a[i] == x)
            ++cnt;
    return cnt;
}