Stair case problem

 

Problem Description

There are n stairs, a person standing at the bottom wants to reach the top. The person can climb either 1 stair or 2 stairs at a time.

• Count the number of ways, the person can reach the top.

 Coding in c:

#include  <stdio.h>

int calc(int n);  

int count(int x);

 

int main ()

{

  int n ;

  printf("Enter number of stairs : ");

  scanf("%d", &n);

  printf("Number of ways = %d", count(n));

  getchar();

  return 0;

}

int count(int x)

{

return calc(x + 1);

}

int calc(int n)

{

   if (n <= 1)

  return n;

   return calc(n-1) + calc(n-2);

}

Output:

Enter number of stairs : 7

Number of ways = 21