Each element in V3 will be the difference of the corresponding elements in V1 and V2Example
const int N = 1000;
vector
vector
vector
iota(V1.begin(), V1.end(), 1);
fill(V2.begin(), V2.end(), 75);
assert(V2.size() >= V1.size() && V3.size() >= V1.size());
transform(V1.begin(), V1.end(), V2.begin(), V3.begin(), minus