Time complexity

#1

Predict the time complexity of the following recursive function, given the vector is of size N and the initial call is calSum(v, 0).

int sum = 0;
void calcSum(vector v, int i)
{
if(i == v.size())
return;
sum += v[i];
calcSum(v, i+1);
}

How the time complexity is O(N^2) in this case?

#2

@sushil_d_loser
assumming vector is defined as vector< int > v
its time complexity will be O(n^2).
because total n calls wiil be there and on every call vector get copied to new vector which is O(n) for each call . therefore O(n^2) for n calls