// Very slow, does not take advantage of overlapping subproblems
// of calculating the same Fibonacci number
// Can be improved with tabulation- dyanamic programming, q4
//
// Run Time Complexity: O(2^N)
// Space Complexity: O(N) with function stacks
int RecursiveFibonacci(int n)
{
if (n <= 1)
return n;
return RecursiveFibonacci(n - 1) + RecursiveFibonacci(n - 2);
}
int main(int argc, char *argv[], char *envp[]) {
int n = 6;
// Recursive Fibonacci
int x = RecursiveFibonacci(n);
printf("Recursive Fibonacci: %d\n", x);
int *fib = NULL;
// Bottom Up Fibonacci
fib = (int *)calloc((size_t)n, sizeof(int));
if (fib == NULL) {
printf("Memory Allocation Error.\n");
return -1;
}
x = BottomUpFibonacci(n, fib);
printf("Bottom up Fibonacci: %d\n", x);
free(fib);
// Top Down Fibonacci
fib = (int *)calloc((size_t)n, sizeof(int));
if (fib == NULL) {
printf("Memory Allocation Error.\n");
return -1;
}
x = TopDownFibonacci(n, fib);
printf("Top Down Fibonacci: %d\n", x);
free(fib);
// Non-DP Fibonacci
x = NonDpFibonacci(n);
printf("Non-DP Fibonacci: %d\n", x);
// Recursive Fact
x = RecursiveFact(n);
printf("Recursive Fact: %d\n", x);
int *facto = NULL;
// DP Fact
facto = (int *)calloc((size_t)n, sizeof(int));
if (facto == NULL) {
printf("Memory Allocation Error.\n");
return -1;
}
x = DpFact(n, facto);
printf("DP Fact: %d\n", x);
return 0;
}
int main ()
{
printf("%d", RecursiveFibonacci(20));
return 0;
}
