#include <cstdint>
#include <optional>

// Standalone arithmetic example. Process/exit validation belongs to the runner.
std::optional<double> ScoredSeconds(
    uint64_t processStart, uint64_t processEnd,
    uint64_t loadStart, uint64_t loadEnd, bool loadCompleted)
{
    if (!loadCompleted || processStart == 0 ||
        processEnd < processStart || loadStart < processStart ||
        loadEnd < loadStart || loadEnd > processEnd) return std::nullopt;
    const uint64_t raw = processEnd - processStart;
    const uint64_t load = loadEnd - loadStart;
    if (raw <= load) return std::nullopt;
    return static_cast<double>(raw - load) / 1e9;
}