Step by Step solution about How to resolve the algorithm String prepend step by step in the C++ programming language

The code snippet you provided is a C++ program that demonstrates the use of the std::accumulate function to concatenate a vector of strings. Here's a detailed explanation of the code:

1. #include <vector>: This line includes the C++ Standard Library header file that provides the std::vector class, which is used to represent a dynamically-sized array of elements.

2. #include <algorithm>: This line includes the C++ Standard Library header file that provides the std::accumulate function, which is used to reduce a sequence of values into a single value.

3. #include <string>: This line includes the C++ Standard Library header file that provides the std::string class, which is used to represent a string of characters.

4. #include <iostream>: This line includes the C++ Standard Library header file that provides the std::cout object, which is used to write data to the standard output stream (usually the console).

5. int main() : This is the entry point of the program. It defines the main function, which is called when the program starts.

6. std::vector<std::string> myStrings { "prepended to" , "my string" } : This line declares a std::vector named myStrings and initializes it with two strings: "prepended to" and "my string".

7. std::string prepended = std::accumulate( myStrings.begin( ), myStrings.end( ), std::string( "" ) , []( std::string a , std::string b ) { return a + b ; } ) : This line uses the std::accumulate function to concatenate the strings in the myStrings vector. Here's how this line works:

   • myStrings.begin(): This returns an iterator pointing to the first element of the myStrings vector.

   • myStrings.end(): This returns an iterator pointing to the element beyond the last element of the myStrings vector.

   • std::string( "" ): This creates an empty string object, which serves as the initial value for the accumulation.

   • []( std::string a , std::string b ) { return a + b ; }: This is a lambda function that takes two std::string arguments and returns the concatenation of those strings.

   • The std::accumulate function calls the lambda function for each pair of adjacent elements in the myStrings vector and accumulates the results into the prepended string variable.

8. std::cout << prepended << std::endl ;: This line uses the std::cout object to print the prepended string to the standard output stream, followed by a newline character (std::endl).

9. return 0 ;: This line indicates the end of the main function and the end of the program. It returns 0 to the operating system, indicating that the program executed successfully.

include <vector>
#include <algorithm>
#include <string>
#include <iostream>

int main( ) {
   std::vector<std::string> myStrings { "prepended to" , "my string" } ;
   std::string prepended = std::accumulate( myStrings.begin( ) , 
	 myStrings.end( ) , std::string( "" ) , []( std::string a , 
	    std::string b ) { return a + b ; } ) ;
   std::cout << prepended << std::endl ;
   return 0 ;
}