Given a string, return a new string where there are i copies of each individual character, where i is the loop index. (That is there will be 0 copies of the first character, 1 of the second, and so on.) Complete the following file: main.cpp 1 #include 2 using namespace std; 3 4 string expando(const string& s) 5 { 6 string result; 7 for(int c 0; c