Question 3 in STL quiz 2

#1

Can you tell how is time complexity O(n^2)?

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);

}

#2

@roopali1710 hey,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

#3

If we use simply array instead of vector, then what would be the time complexity in this case?

#4

@roopali1710 Then complexity will be O(n).

#5

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