int main()
{
{
std::chrono::time_point<std::chrono::system_clock> start, end;
start = std::chrono::system_clock::now();
std::cout << "sum_recursive(100) = " << sum_recursive(100) << '\n';
end = std::chrono::system_clock::now();
std::chrono::duration<double> elapsed_seconds = end-start;
std::time_t end_time = std::chrono::system_clock::to_time_t(end);
std::cout << "finished computation at " << std::ctime(&end_time)
<< "elapsed time: " << elapsed_seconds.count() << "s\n";
}
{
std::chrono::time_point<std::chrono::system_clock> start, end;
start = std::chrono::system_clock::now();
std::cout << "sum_loop(100) = " << sum_loop(100) << '\n';
end = std::chrono::system_clock::now();
std::chrono::duration<double> elapsed_seconds = end-start;
std::time_t end_time = std::chrono::system_clock::to_time_t(end);
std::cout << "finished computation at " << std::ctime(&end_time)
<< "elapsed time: " << elapsed_seconds.count() << "s\n";
}
}
int sum_recursive(int num, int counter) {
if (counter == num) {
return num;
} else {
return counter + sum_recursive(num, counter+1);
}
}
int sum_recursive(struct listNode* x)
//@ rule <k> $ => return sum(A); ...</k> <heap>... list(x)(A) ...</heap>
{
if (x == NULL)
return 0;
return x->val + sum_recursive(x->next);
}
int main(int argc, char *argv[]) {
if (argc != 2) {
fprintf(stderr, "Usage: %s number\n", argv[0]);
return EXIT_FAILURE;
}
int sum = sum_recursive(atoi(argv[1]), 0);
printf("Recursive sum = %d\n", sum);
return EXIT_SUCCESS;
}
int main()
{
{
std::chrono::time_point<std::chrono::system_clock> start, end;
start = std::chrono::system_clock::now();
std::cout << "sum_recursive(100) = " << sum_recursive(100) << '\n';
end = std::chrono::system_clock::now();
std::chrono::duration<double> elapsed_seconds = end-start;
std::cout << "sum_recursive elapsed time: " << elapsed_seconds.count() << "s\n";
}
{
std::chrono::time_point<std::chrono::system_clock> start, end;
start = std::chrono::system_clock::now();
std::cout << "sum_loop(100) = " << sum_loop(100) << '\n';
end = std::chrono::system_clock::now();
std::chrono::duration<double> elapsed_seconds = end-start;
std::cout << "sum_loop elapsed time: " << elapsed_seconds.count() << "s\n";
}
}
long sum_recursive(unsigned n)
{
if (n == 1) return n;
return sum_recursive(n-1) + n;
}
