Step by Step solution about How to resolve the algorithm Associative array/Merging step by step in the C++ programming language

The provided C++ code defines a generic merge function to merge two maps of the same type and a main function to demonstrate its usage. Let's break down the code step by step:

1. Template Function merge:

   • This function is a generic function template that takes two maps of the same type (map_type) as input parameters and returns a new map (also of type map_type) as the result.
   • Inside the function:
     • It creates a new map called result initialized with the data from update.
     • It inserts all elements from original into result using result.insert(original.begin(), original.end()). This effectively merges the elements of both maps.
     • Finally, the result map is returned as the result of the merge.

2. main Function:

   • It uses std::map<std::string, std::string> to define a map type called map that maps strings to strings.
   • It creates two map objects:
     • original is initialized with three key-value pairs:
       • "name": "Rocket Skates"
       • "price": "12.75"
       • "color": "yellow"
     • update is initialized with three key-value pairs:
       • "price": "15.25"
       • "color": "red"
       • "year": "1974"
   • It calls the merge function with original and update as arguments and stores the result in a new map object called merged.
   • Finally, it iterates through the merged map using a range-based for loop and prints each key-value pair to the console in the format "key: , value: ".

In summary, this code demonstrates how to merge two maps of the same type using a generic merge function template. It creates two sample maps (original and update), merges them, and prints the merged map's contents.

#include <iostream>
#include <string>
#include <map>

template<typename map_type>
map_type merge(const map_type& original, const map_type& update) {
    map_type result(update);
    result.insert(original.begin(), original.end());
    return result;
}

int main() {
    typedef std::map<std::string, std::string> map;
    map original{
        {"name", "Rocket Skates"},
        {"price", "12.75"},
        {"color", "yellow"}
    };
    map update{
        {"price", "15.25"},
        {"color", "red"},
        {"year", "1974"}
    };
    map merged(merge(original, update));
    for (auto&& i : merged)
        std::cout << "key: " << i.first << ", value: " << i.second << '\n';
    return 0;
}