Answers for "what is the fibonacci"

fibonacci

# WARNING: this program assumes the
# fibonacci sequence starts at 1
def fib(num):
	"""return the number at index `num` in the fibonacci sequence"""
    if num <= 2:
        return 1
    return fib(num - 1) + fib(num - 2)

# method 2: use `for` loop
def fib2(num):
	a, b = 1, 1
	for _ in range(num - 1):
		a, b = b, a + b
	return a


print(fib(6))  # 8
print(fib2(6))  # same result, but much faster

fibonacci

# Easy fibonacci exercise
# Method #1
def fibonacci(n):
    # 1th: 0
    # 2th: 1
    # 3th: 1 ...
    if n == 1:
        return 0
    elif n == 2:
        return 1
    else:
        return fibonacci(n - 1) + fibonacci(n - 2)

# Method #2
def fibonacci2(n):
    if n == 0: return 0
    n1 = 1
    n2 = 1
    # (1, n - 2) because start by 1, 2, 3... not 0, 1, 1, 2, 3....
    for i in range(1, n - 2):
        n1 += n2
        n2 = n1 - n2
    return n1


print(fibonacci(13))
# return the nth element in the fibonacci sequence

fibonacii

#include<stdio.h>
#include<conio.h>

void fibonacci(int num);
void main()
{
    int num = 0;
    clrscr();
    printf("Enter number of terms\t");
    scanf("%d", &num);
    fibonacci(num);
    getch();
}

void fibonacci(int num)
{
   int a, b, c, i = 3;
   a = 0;
   b = 1;
   if(num == 1)
   printf("%d",a);

   if(num >= 2)
   printf("%d\t%d",a,b);

   while(i <= num)
   {
      c = a+b;
      printf("\t%d", c);
      a = b;
      b = c;
      i++;
   }
}