Question

c++

std::string addStar(const std::string &str); // Task: Given a string, compute recursively a new string where all the adjacent // Pre: str is a string (may be empty). // Post: a correctly starred string is returned // Examples: //し.addStar("hello") →Xh*e*W*o" /1 addStar("abc")"axb*c" // addStar("ab" )-→ "a*b"

Answer 1

// helper method
std::string addStarhelp(const std::string &str, int idx)
{
// base call
int len = str.size();
if(idx == len-1 )
return str[len-1];

// recursive call
  
return str[idx] + "*" + addStarhelp(str,idx+1);
}

// addstar uses helper method to add start to string
std::string addStar(const std::string &str)
{
return addStarhelp(str, 0);
}