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

bool IsEven(int n) {
    return (n % 2) == 0;
}

int main() {
    // Test vector
    vector<int> vec{ 11, 22, 33, 44, 55 };
    
    // Using functional approach
    auto n = count_if(vec.begin(), vec.end(),
         bind(logical_not<bool>(),
             bind(modulus<int>(), placeholders::_1, 2)));    
    cout << n << endl;

    // Using lambdas
    n = count_if(vec.begin(), vec.end(), 
                 [](int n) { return (n % 2) == 0; });
    cout << n << endl;
    
    // Using boolean returning ad hoc function
    n = count_if(vec.begin(), vec.end(), IsEven);
    cout << n << endl;
}