74.
What is the space complexity of the recursive implementation used to convert a decimal number to its binary equivalent?
#include<stdio.h>
int arr[31], len = 0;
void recursive_dec_to_bin(int n)
{
      if(n == 0 && len == 0)
      {
          arr[len++] = 0;
          return;
      }
      if(n == 0)
         return;
      arr[len++] = n % 2;
      recursive_dec_to_bin(n/2);
}

75.
Consider the following code:
#include<stdio.h>
int arr[31], len = 0;
void recursive_dec_to_bin(int n)
{
      if(n == 0 && len == 0)
      {
          arr[len++] = 0;
          return;
      }
      if(n == 0)
         return;
      arr[len++] = n % 2;
      recursive_dec_to_bin(n/2);
}
Which of the following lines is the base case for the above code?

78.
What is the output of the following code?
#include<stdio.h>
int recursive_sum(int n)
{
      if(n == 0)
        return 0;
      return n + recursive_sum(n - 1);
}
int main()
{
      int n = 5;
      int ans = recursive_sum(n);
      printf("%d",ans);
      return 0;
}