Python Coding challenge - Day 524| What is the output of the following Python Code?

 

Code Explanation:

1. Function Definition

def climb_stairs(n):

Defines a function named climb_stairs that takes one argument n, representing the number of steps.

2. Base Case Check

    if n <= 2:

        return n

If n is 1 or 2, return n directly because:

For 1 step, there is only 1 way.

For 2 steps, there are 2 ways (1+1 or 2).

3. Initialize Variables

    a, b = 1, 2

Initialize two variables:

a represents the number of ways to climb to step 1 (which is 1).

b represents the number of ways to climb to step 2 (which is 2).

4. Loop Through Steps 3 to n

    for _ in range(3, n + 1):

        a, b = b, a + b

For each step from 3 to n:

Update a to the previous b (ways to reach the previous step).

Update b to the sum of the previous a and b (ways to reach current step).

This uses the Fibonacci pattern because ways to get to step i = ways to get to i-1 + ways to get to i-2.

5. Return Result

    return b

After the loop, b holds the total number of ways to reach step n, so return it.

6. Function Call and Output

print(climb_stairs(5))

Calls the function with n = 5 and prints the result.

Output will be 8, which is the number of ways to climb 5 steps.

Output:

8