Replace an element into a specific position of a vector

Question

I want to replace an element into a specific position of a vector, can I just use an assignment:

// vec1 and 2 have the same length & filled in somehow
v         


        

Answer 1

vec1[i] = vec2[i]

will set the value of vec1[i] to the value of vec2[i]. Nothing is inserted. Your second approach is almost correct. Instead of +i+1 you need just +i

v1.insert(v1.begin()+i, v2[i])