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Revision ced7ef9d59d02954961594d22aab142352d3018b

speed.c Raw
1#include <gmp.h>
2#include <stdio.h>
3#include <stdlib.h>
4#include <time.h>
5
6int main(int argc, char *argv[]) {
7 // Get the limit from the first argument
8 if (argc != 2) {
9 printf("Wrong input.\n");
10 printf("Usage: howfast <limit>\n");
11 return EXIT_FAILURE;
12 }
13
14 long int limit = strtol(argv[1], NULL, 10);
15
16 // Setup GMP arithmetic library
17 mpz_t a;
18 mpz_t b;
19 mpz_t c;
20
21 mpz_init_set_ui(a, 1);
22 mpz_init_set_ui(b, 0);
23 mpz_init(c);
24
25 // Start timer
26 const clock_t start = clock();
27
28 // Fibonacci calculation
29 for (long int i = 0; i < limit; ++i) {
30 mpz_add(c, a, b);
31 mpz_set(a, b);
32 mpz_set(b, c);
33 }
34
35 // End timer
36 const clock_t end = clock();
37
38 // Print the result
39 printf("Fibonacci number %ld: ", limit);
40 mpz_out_str(stdout, 10, b);
41 printf("\n");
42
43 // Clean up
44 mpz_clear(a);
45 mpz_clear(b);
46 mpz_clear(c);
47
48 // Print time
49 double time_taken = ((double)(end - start)) / CLOCKS_PER_SEC;
50 printf("Time: %f seconds\n", time_taken);
51 return EXIT_SUCCESS;
52}