Question

Write a function with this prototype:
#include
void numbers(ostream& outs, const string& prefix, unsigned int levels);
The function prints output to the ostream outs. The output consists of the String prefix followed by "section numbers" of the form 1.1., 1.2., 1.3., and so on. The levels argument determines how many levels the section numbers have. For example, if levels is 2, then the section numbers have the form x.y. If levels is 3, then section numbers have the form x.y.z. The digits permitted in each level are always '1' through '9'. As an example, if prefix is the string "THERBLIG" and levels is 2, then the function would start by printing:
THERBLIG1.1.THERBLIG1.2.THERBLIG1.3.and ends by printing:THERBLIG9.7.THERBLIG9.8.THERBLIG9.9.The stopping case occurs when levels reaches zero (in which case the prefix is printed once by itself followed by nothing else).The string class from has many manipulation functions, but you'll need only the ability to make a new string which consists of prefix followed by another character (such as '1') and a period ('.'). If s is the string that you want to create and c is the digit character (such as '1'), then the following statement will correctly form s:s = (prefix + c) + '.';This new string s can be passed as a parameter to recursive calls of the function.

Answer 1

Answer:

Following are the code to this question:

#include <iostream> //defining header file  

using namespace std;

void numbers(ostream &outs, const string& prefix, unsigned int levels); // method declaration

void numbers(ostream &outs, const string& prefix, unsigned int levels) //defining method number

{

string s; //defining string variable

if(levels == 0) //defining condition statement that check levels value is equal to 0

{

outs << prefix << endl;  //use value

}

else //define else part

{

for(char c = '1'; c <= '9'; c++) //define loop that calls numbers method

{

s = prefix + c + '.'; // holding value in s variable  

numbers(outs, s, levels-1); //call method numbers

}

}

}

int main() //defining main method

{

numbers(cout, "THERBLIG", 2); //call method numbers method that accepts value

return 0;

}

Output:

please find the attachment.

Explanation:

Program description:

• In the given program, a method number is declared, that accepts three arguments in its parameter that are "outs, prefix, levels", and all the variable uses the address operator to hold its value.
• Inside the method a conditional statement is used in which string variable s and a conditional statement is used, in if the block it checks level variable value is equal to 0. if it is false it will go to else block that uses the loop to call method.
• In the main method we call the number method and pass the value in its parameter.