#include <stdio.h>
#include <stdlib.h>
#include <time.h>
void O_n (long int n, double *s, double *p)
        {
                double Suma = 0.;
                int a = 0;
                double Proizvod = 1.;
                for (; a < n; ++a)
                        Suma += a, Proizvod *= a;
                *s = Suma;
                *p = Proizvod;
        }
void O_2n (long int n, double *s, double *p)
        {
                double Suma = 0.;
                int a = 0;
                double Proizvod = 1.;
                for (; a < n; ++a)
                        Suma += a;
                for (a = 0; a < n; ++a)
                        Proizvod *= a;
                *s = Suma;
                *p = Proizvod;
        }
int main ()
        {
                int n = 10000000, m = 1000, a = 0;
                double P1, P2, S1, S2, V1, V2;
                clock_t T1 = clock(), T2;
                for (; a < m; ++a)
                        O_n (n, &S1, &P1);
                T2 = clock();
                V1 = (T2 - T1) / (CLOCKS_PER_SEC/1000.);
                T1 = clock();
                a = 0;
                for (; a < m; ++a)
                        O_2n (n, &S2, &P2);
                T2 = clock();
                V2 = (T2 - T1) / (CLOCKS_PER_SEC/1000.);
                printf("Vrijeme 1 za O(n), pri n = %i, a m = %i je: %.1f ms.\n", n, m, V1);
                printf("Vrijeme 2 za O(2n), pri n = %i, a m = %i je: %.1f ms.\n", n, m, V2);
                return 0;
 
        }