Ways to climb N stairs

 Coding Problem Keys 

 Ways to climb N stairs 

 Problem Statement 

There are N stairs to climb before reaching an office. The employee can either climb 1 stair or 2 stair at in a single step. The program must print the count of distinct ways for and employee to climb the N stairs.

 Input Format 

The first line will contain the value of N.

 Output Format 

The first line will contain the number of distinct ways to climb the N stair.

 Boundary Condition(s) 

1 <= N <= 99

 Example Input/Output 1 

 Input 

1

 Output 

1

 Example Input/Output 2 

 Input 

2

 Output 

2

 Explanation 

The steps can be 1, 1 or as 2.

 Example Input/Output 3 

 Input 

5

 Output 

8

 Explanation 

The steps can be

1, 1, 1, 1, 1 or

1, 1, 1, 2 or

1, 2, 2 or

1, 1, 2, 1 or

1, 2, 1, 1 or

2, 2, 1 or

2, 1, 2 or

2, 1, 1, 1.

 Note: Max Execution Time Limit: 5000 millisecs 

 Solution 

 Programming Language: Python 3 Language 

n=int(input())
a=0;b=1;c=1
for i in range(n-1):
    c=a+b
    a=b
    b=c
print(c+a)

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 Alter 

n=int(input());a=1;b=0;result=0
if n<=0: print(0); exit()
if n==1: print(1); exit()
for i in range(1,n+1):
    result=a+b
    b=a
    a=result
print(result)

# Published By PKJCODERS

 (Note: Incase If the code doesn't Pass the output kindly comment us with your feedback to help us improvise.)