# Data Structure Questions and Answers-Sum of n Natural Numbers using Recursion

## Data Structure Questions and Answers-Sum of n Natural Numbers using Recursion

 Question 11 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
How many times is the function recursive....sum() called when the following code is executed?

`#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; }`
 A 4 B 5 C 6 D 7
Question 11 Explanation:
The function recursive....sum is called 6 times when the following code is executed.

 Question 12 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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 = 0; int ans = recursive....sum(n); printf("%d", ans); return 0; }`
 A -1 B 0 C 1 D runtime error
Question 12 Explanation:
The program prints the sum of first 0 natural numbers, which is 0.

 Question 13 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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 = -4; int ans = recursive....sum(n); printf("%d", ans); return 0; }`
 A 0 B -10 C 1 D runtime error
Question 13 Explanation:
The above code doesn't handle the case of negative numbers and so the function recursive....sum() will be called again and again till the stack overflows and the program produces a runtime error.

There are 13 questions to complete.