Advent of code 2021 - day1 - solution

advent-of-code-2021-day1.cpp

#include <iostream>
#include <boost/format.hpp>
#include <day1.hpp>

namespace day1
{
    std::string solution(std::istream &std_input)
    {
        int increased = 0;
        int prev, curr;
        std::string line;

        std::getline(std_input, line);
        prev = std::stoi(line);

        while (std::getline(std_input, line))
        {
            curr = std::stoi(line);
            if (curr > prev)
            {
                increased++;
            }
            prev = curr;
        }
        return (boost::format("%d") % increased).str();
    }
}