blcArmadillo blcArmadillo - 1 month ago 14
C++ Question

Recursive Fibonacci

I'm having a hard time understanding why

#include <iostream>

using namespace std;

int fib(int x) {
if (x == 1) {
return 1;
} else {
return fib(x-1)+fib(x-2);
}
}

int main() {
cout << fib(5) << endl;
}


results in a segmentation fault. Once x gets down to 1 shouldn't it eventually return?

Answer

When x==2 you call fib(1) and fib(0):

return fib(2-1)+fib(2-2);

Consider what will happen when fib(0) is evaluated...

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