Let us take a look at all the ways using which we can solve this problem.
Method 1: Using simple addition
def get_nth_fibonacci(n): a = 0 b = 1 if n < 0: print("Incorrect input. You cannot enter 0") elif n == 0: return a elif n == 1: return b else: for i in range(2, n): c = a + b a = b b = c return b n = int(input("Enter the n-th fibonacci number you want: ")) print("The",n,"th fibonacci number is: ",get_nth_fibonacci(n))
Enter the n-th fibonacci number you want: 10 The 10 get_nth_fibonacci number is: 34
Here for 0 and 1, we defined conditions and for the other numbers we used else statements. Inside the else statement, we used a for loop that will run over the range from 2 to the number entered by the user. Now we add the first two numbers of Fibonacci and then assign the value of b in a and value of c in b. This will continue till the value of ” i “ reaches the mentioned range.
Method 2: Using append()
def get_nth_fibonacci(n): if n <= 0: return "Incorrect Output" data = [0, 1] if n > 2: for i in range(2, n): data.append(data[i-1] + data[i-2]) return data[n-1] n = int(input("Enter the n-th fibonacci number you want: ")) print("The",n,"th fibonacci number is: ",get_nth_fibonacci(n))
Here we defined the condition as stated for value 0 and for n > 2, we used for loop and as we go along we append the value that is computed by data[i-1] + data[i-2]. Decoding this for n = 10, then our first appended value will be data[2-1] + data[2-2] = data + data and the output will be 1+0 = 1. Now, this value will be appended to the list and this will continue till n reaches 9 because the last number in the range is excluded.
Here are the two approaches to solving the laid problem.