Question

Please Write Code in C++ and include the correct #include <header> and not a catchall such as bits/stdc:

Write a recursive, string-valued function, replace, that accepts a string and returns a new string consisting of the original string with each blank replaced with an asterisk (*)

Replacing the blanks in a string involves:

• Nothing if the string is empty
• Otherwise:
  • If the first character is not a blank, simply concatenate it with the result of replacing the rest of the string
  • If the first character is a blank, concatenate an * with the result of replacing the rest of the string

Answer 1

Code

#include<iostream>
using namespace std;

string rec(string s,int c)
{
    if(s.empty() && c==0) //if c==0 then string is processing for first time and empty() defines empty string hence return nothing
        return "Nothing";
    if(s.empty() && c!=0) //c!=1 defines non empty string passed hence no need to add "nothing" at end hence return ""
        return "";
    c++;
    if(s[0]==' ')
        return "*"+rec(s.substr(1),c);
    return s[0]+rec(s.substr(1),c);
}
int main()
{
    string s; 
    cout<<"Enter the string:\n";
    getline(cin,s); //get input string from user
    int c=0; //helps to decide return nothing or ""
    string res=rec(s,c);
    cout<<"Modified string is:\n"<<res;
    return 0;
}

Terminal Work

.

​​​​​