Найти минимальный по модулю элемент массива

#include <iostream>
#include <vector>
#include <algorithm>
 
using namespace std;
 
void foo() {
          int one(0);
    std::vector<int> v = {20, 1, 23, -2, 55, 3 };
    
    for (auto i = v.begin(); i != v.end(); ++i){
bool ex = false;
        one = abs(*i);
//====================================================  
        for (auto in = v.begin(); in != v.end(); ++in)
        if (one > abs(*in)) ex = true;
            
        if (ex == false) break;
                    }
        printf(" ==========> %d \n", one);
          }

#include <iostream>
#include <algorithm>
#include <random>
#include <vector>
#include <iterator>
#include <cmath>
 
int main()
{
    using std::cout;
    std::mt19937 gen(std::random_device{}()); //Standard mersenne_twister_engine seeded with rd()
    std::uniform_real_distribution<> dis(-20.0, 20.0);
    constexpr size_t NUMBERS_C = 20;
    std::vector<double> vec;
    vec.reserve(NUMBERS_C);
    std::generate_n(std::back_inserter(vec), NUMBERS_C, [&dis,&gen](){return dis(gen);});
    cout << "Array : ";
    std::copy(vec.begin(), vec.end(), std::ostream_iterator<decltype(vec)::value_type>(cout, " "));
    cout << std::endl;
    auto condition = [](const auto& lhs, const auto& rhs){
      return std::fabs(lhs) < std::fabs(rhs);
    };
    auto result = std::min_element(vec.begin(), vec.end(), condition);
    cout << "Min element by modulus in the vector is : " << *result;
}

#include <iostream>
#include <cfloat>
#include <cmath>
using namespace std;
 
int main()
{
    int n;
    cout << "n="; cin >> n;
 
      double *a = new double[n], min=DBL_MAX;
 
    cout << "Enter " << n << " numbers:\n";
    for (int i = 0; i < n; i++)
    {
        cin >> a[i];
        if (fabs(a[i]) < fabs(min)) min=a[i];
    }    
        
    cout << "min by modulo: " << min << "\n";    
 
    delete[]a;
system("pause");
return 0;
}

    auto condition = [](const decltype(vec)::value_type& lhs, const decltype(vec)::value_type& rhs){
      return std::fabs(lhs) < std::fabs(rhs);
    };

template <typename T>
T foo(T first, T last)
{
    T res { first };
    while(++first < last)
        if(fabs(*res) > fabs(*first))
            res = first;
 
    return res;
}