AoC22/d04.cc

#include <iostream>
#include <vector>
#include <array>
#include <algorithm>

using namespace std;

struct Range {
    unsigned min;
    unsigned max;

    bool contains(const Range &in) const {
        return min <= in.min && max >= in.max;
    }

    bool overlaps(const Range &in) const {
        return min <= in.max && in.min <= max;
    }
};

typedef vector<array<Range, 2>> Input;

Input parse()
{
    Input data;
    for (string line; getline(cin, line);) {
        array<Range, 2> entry;
        sscanf(line.c_str(), "%u-%u,%u-%u",
                &entry[0].min, &entry[0].max,
                &entry[1].min, &entry[1].max);
        data.push_back(entry);
    }
    return data;
}

unsigned p1(const Input &input)
{
    return count_if(input.begin(), input.end(), [](decltype(input[0]) i){
        return i[0].contains(i[1]) || i[1].contains(i[0]);
    });
}

unsigned p2(const Input &input)
{
    return count_if(input.begin(), input.end(), [](decltype(input[0]) i){
        return i[0].overlaps(i[1]);
    });
}

int main()
{
    auto input = parse();
    cout << p1(input) << endl;
    cout << p2(input) << endl;
}