Question

1. Copy d_state.h to your working directory and finish its implementation.
2. Write a program:
   • it first declares a set object s having 5 elements of type stateCity with its initial values such as ("Virginia", "Richmond");
   • then perform the search: input the name of a state, and use the find() function to determine where the state in the set. If the object is present, used the << operator to output the sate and the city; if it is not present, output a message to that effect.
   • Then, rather than using objects of type stateCity, you will implement the program by using a map with state name (string) as the key and the city name (string) as the data value.

d_state.h:

#ifndef STATECITY_CLASS
#define STATECITY_CLASS

#include 
#include 

using namespace std;

// object stores the state name and city in the state
class stateCity
{
        public:
                stateCity (const string& name = "", const string& city = "");

                // output the state and city name in the format
                //    cityName, stateName
                friend ostream& operator<< (ostream& ostr, const stateCity& state;
                
                // operators < and == must be defined to use with set object.
                // operators use only the stateName as the key
                friend bool operator< (const stateCity& a, const stateCity& b);
                
                friend bool operator== (const stateCity& a, const stateCity& b);
        
        private:
                string stateName, cityName;
};

#endif  // STATECITY_CLASS

Please write in C++

Sample Output:

Run 1:

Enter a state: Arizona

Phoenix, Arizona

Run 2:

Enter a state: New York

New York is not in the set

Answer 1

Code in C++ for main.cpp (code to copy)

#include <bits/stdc++.h>
#include "d_state.h"
using namespace std;


int main(){
        set<stateCity> s = {stateCity ("Virginia", "Richmond"), stateCity ("Arizona", "Phoenix"), stateCity ("New Hampshire", "Warner"), stateCity ("Kansas", "Scottsville"), stateCity ("Texas", "Longview")};
        cout<<"Enter a state: ";
        string state;
        cin>>state;
        auto it = s.find(stateCity(state));
        if(it==s.end()){
                cout<<state<<" is not in the set"<<endl;
        }else{
                cout<<*it<<endl;
        }
}

code in c++ for d_state.h (code to copy)

#ifndef STATECITY_CLASS
#define STATECITY_CLASS

#include<bits/stdc++.h>

using namespace std;

// object stores the state name and city in the state
class stateCity
{
        public:
                stateCity (const string& name = "", const string& city = ""){
                    stateName=name;
                    cityName=city;
                }

                // output the state and city name in the format
                //    cityName, stateName
                friend ostream& operator<< (ostream& ostr, const stateCity& state){
                    ostr<<state.cityName<<" "<<state.stateName;
                }
                
                // operators < and == must be defined to use with set object.
                // operators use only the stateName as the key
                friend bool operator< (const stateCity& a, const stateCity& b){
                    return a.stateName<b.stateName;
                }
                
                friend bool operator== (const stateCity& a, const stateCity& b){
                    return a.stateName==b.stateName;
                }
        
        private:
                string stateName, cityName;
};

#endif  // STATECITY_CLASS

Code screenshot main.cpp

Code screenshot d_state.h

Sample output screenshot 1

Sample Output screenshot 2

Let me know in the comments if you have any doubts.
Do leave a thumbs up if this was helpful.