/* Fast Fibonacci. */
long long int fastfib(int n)
{
fastfib_execs++;
if (n <= 2)
return (n+1)/2;
int half = n/2;
return n % 2 == 0 ?
fastfib(half) * (2 * fastfib(half + 1) - fastfib(half)) :
sq(fastfib(half+1)) + sq(fastfib(half));
}
int main()
{
unsigned int n = 0;
if (n == 0)
{
if (n == 1) {
printf("Hello\n!");
}
}
for(n=0; n<35; ++n)
printf("fib(%u)=%u\n", n, fib(n));
for(n=0; n<35; ++n)
printf("fastfib(%u)=%u\n", n, fastfib(n));
for(n=0; n<35; ++n)
printf("fastfib_v2(%u)=%u\n", n, fastfib(n));
return 0;
}
/* Dynamic programming. */
int main(int argc, char **argv)
{
int n;
n = 30;
/* Table. */
int size = 100;
if (!(table = calloc(size, sizeof(long long int)))) return 1;
/* Execution counts. */
dynpfib_execs = 0;
fastfib_execs = 0;
fib_execs = 0;
dynpfib(n);
fastfib(n);
fib(n);
/* Times. */
printf("usual=%lld fast=%lld dynprog=%lld\n", fib_execs, fastfib_execs, dynpfib_execs);
return EXIT_SUCCESS;
}
