element-wise multiplication of two vectors in c++

Question

I am trying to do the following mathematical operation with two vectors:

v1 = [a1][a2][a3][a4][a5]
v2 = [b1][b2][b3][b4]b5]

Want to compute:

Answer 1

You could look into std::valarray. It's designed to allow mathematical operations on every element in the array.

Answer 2

std::transform( v1.begin()+1, v1.end(),
                v2.begin()+1, v.begin(),  // assumes v1,v2 of same size > 1, 
                                          //       v one element smaller
                std::multiplies<int>() ); // assumes values are 'int'

You can replace v.begin() with std::back_inserter(v) if v is empty, you should reserve() memory upfront to avoid multiple allocations.