c++ 计算程序耗时

惊喜存档。

https://en.cppreference.com/w/cpp/chrono

 计算程序耗时时间。

#include 
#include 
 
long fibonacci(unsigned n)
{
    if (n < 2) return n;
    return fibonacci(n-1) + fibonacci(n-2);
}
 
int main()
{
    auto start = std::chrono::steady_clock::now();
    std::cout << "f(42) = " << fibonacci(42) << 'n';
    auto end = std::chrono::steady_clock::now();
    std::chrono::duration elapsed_seconds = end-start;
    std::cout << "elapsed time: " << elapsed_seconds.count() << "sn";
}