Cpp program not giving output - c++

Question

I am creating a script that calculates the sum of first n Fibonacci numbers and returns the last digit of the sum.
The python script works perfect but the C++ script does not and the logic is same.
Any help will be appreciated.
Python Code
def calc_fib(n):
f = [0, 1]
for i in range(2, 61):
f.insert(i, (f[i-1] + f[i-2]) % 10)
rem = n % 60
quotient = (n - rem) / 60
return int((sum(f) * quotient + sum(f[0: rem+1])) % 10)
n = int(input())
print(calc_fib(n))
C++ Code
#include <iostream>
#include <vector>
#include <numeric>
using namespace std;
long long fibonacci_sum_last_digit(long long n) {
vector<int> f(n + 1);
f[0] = 0;
f[1] = 1;
for (int i = 2; i <= 60; i++){
f[i] = (f[i-1] + f[i-2]) % 10;
}
int rem = n % 60;
int quotient = (n - rem) / 60;
return (accumulate(f.begin(), f.end(), 0) * quotient + accumulate(f.begin(), f.begin() + rem + 1, 0)) % 10;
}
int main() {
int n;
cin >> n;
if (n <= 1)
cout << n;
else
cout << fibonacci_sum_last_digit(n) << '\n';
return 0;
}

Answer 1

vector<int> f(n + 1);
f[0] = 0;
f[1] = 1;
for (int i = 2; i <= 60; i++){
f[i] = (f[i-1] + f[i-2]) % 10;
}
The vector is size n+1 and you access until 60 => it's a bug
This should fix :
vector<int> f(60 + 1);
Or
vector<int> f;
f.push_back(0);
f.push_back(1);
for (int i = 2; i <= 60; i++){
f.push_back((f[i-1] + f[i-2]) % 10);
}