Query about CodeChef IDE

general
1

Why an infinite recursive function gives TLE (SIGSTP) in CodeChef IDE instead of giving segmentation fault?
How can 5 second be not enough to fill up the stack size?

Code 
#include <bits/stdc++.h>
using namespace std;

int fun(int n) {
	return fun(n - 1) + fun(n - 2);
}

int main() {
	cout << fun(100) << '\n';
}
3

The compiler might be doing tail call optimisation, in which case the stack space used will be small and constant.

Edit:

Although I’ve just tried this on my machine and it segfaulted after 0.33 seconds, so maybe not :slight_smile: (gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04), with -O3).

3 Likes
4

@admin @vijju123 is this any kind of bug? Just want to know what is actually happening inside.

5

Isn’t SIGSTP error associated to integer overflow?

If you do the same but use modular addition the error message is SIGSEGV