Не могу разобраться в сути работы программы :(

#include <iostream>
 
using namespace std;
 
int main()
{
    int i;
 
    float number, largest, largest2;
 
    cout << "Enter number: ";
    cin >> largest;
    cout << "\nEnter number: ";
    cin >> largest2;
 
    if (largest2 > largest)
    {
        float tmp;
        tmp = largest;
        largest = largest2;
        largest2 = tmp;
    }
 
    for (i = 1; i <= 8; i++)
    {
        cout << "\nEnter number: ";
        cin >> number;
 
        if (number > largest)
        {
            largest2 = largest;
            largest = number;
        }
        else if (number > largest2)
            largest2 = number;
    }
 
    cout << endl << "Max1: " << largest << endl;
    cout << endl << "Max2: " << largest2 << endl;
 
 
    return 0;
}

if (largest2 > largest) {
    float tmp;
    tmp = largest;
    largest = largest2;
    largest2 = tmp;
  }

    if (number > largest) {
      largest2 = largest;
      largest = number;
    } else if (number > largest2)
      largest2 = number;

#include <iostream>
#include <vector>
#include <algorithm>
 
float GetNumberFromUser(std::istream &istream) {
  std::cout << "Enter number: ";
  float number = 0;
  istream >> number;
  return number;
}
 
int main() {
  std::vector<float> numbers;
  for (size_t i = 0; i < 10; ++i) {
    numbers.push_back(GetNumberFromUser(std::cin) * i);
  }
  std::sort(numbers.begin(), numbers.end(), std::greater<float>());
  auto largest_number_it = numbers.begin();
  std::cout << "\nMax1: " << *largest_number_it
            << "\nMax2: " << *std::next(largest_number_it, 1) << '\n';
}

#include <iostream>
#include <vector>
#include <algorithm>
 
float GetNumberFromUser(std::istream &istream) {
  std::cout << "Enter number: ";
  float number = 0;
  istream >> number;
  return number;
}
 
int main() {
  float first_max = GetNumberFromUser(std::cin);
  float second_max = GetNumberFromUser(std::cin);
  for (size_t i = 0; i < 8; ++i) {
    auto current = GetNumberFromUser(std::cin);
    if (first_max < current) {
      second_max = first_max;
      first_max = current;
    } else {
      second_max = std::max(second_max, current);
    }
  }
  std::cout << "\nMax1: " << first_max << "\nMax2: " << second_max << '\n';
}