#include <cstdio>
#include <bitset>
#include <string>
#include <algorithm>


auto bin2str(int num) -> std::string {
    constexpr std::size_t max_position = sizeof(int) * 8;
    std::string str{};
    for (std::size_t i = 0; i < max_position; ++i) {
        str += (num & (1 << i)) ? '1' : '0';
        if ((i + 1) % 8 == 0 && i < max_position - 1) str += "'";
    }
    std::reverse(std::begin(str), std::end(str));
    return str;
}

int solution(int N) {
    constexpr std::size_t max_position = sizeof(int) * 8;
    std::size_t start = 0;
    std::size_t end   = 0;

    std::size_t final_start = 0;
    std::size_t final_end   = 0;

    for (std::size_t i = 0; i < max_position; ++i) {
        bool const is_one_start = (N & (1 << i)) >> i;
        if (is_one_start) {
            start = i;
            for (std::size_t j = start + 1; j < max_position; ++j) {
                bool const is_one_end = (N & (1 << j)) >> j;
                if (is_one_end) {
                    end = j;
                    break;
                }
            }
        } else continue;

        if (end - start > final_end - final_start) {
            final_start = start;
            final_end   = end - 1;
        }
    }

    std::intptr_t size = final_end - final_start;
    if (size > 0) return size;
    else return 0;
}

auto main() -> int {
    int input = 32;
    auto gap  = solution(input);
    std::printf("Input: %d, [%s]\n", input, bin2str(input).c_str());
    std::printf("Gap: %d\n", gap);
    std::printf("%s\n", bin2str(1 << 0).c_str());
    std::printf("%s\n", bin2str(0x2&(1 << 0)).c_str());
    return 0;
}