Question

Write an interactive C++ program that asks a user to input the color code of a resistor and determines its value and tolerance

• Tell the user how to input the color rings “Instructions”
• Tell the user to input the colors one after the other
• After the program receives the information it will display the resistance and tolerance
• Output an error message if the user enters an invalid color code (no garbage values should be displayed), and ask for another input after every display
• Repeat asking for the color code of another resistor until the user says that he/she is done and wants to exit; meaning the program is going to have different options

How to read 4 Color Resistor Codes

First the code

Black	Brown	Red	Orange	Yellow	Green	Blue	Violet	Gray	White
0	1	2	3	4	5	6	7	8	9

Answer 1

Code:

#include<iostream>
#include<map>
using namespace std;
int main()
{
   int total = 0;
   map<string, int>color;//data structure which stores a string value as key and int value as its value
   color["Black"] = 0;//initialising map
   color["Brown"] = 1;
   color["Red"] = 2;
   color["Orange"] = 3;
   color["Yellow"] = 4;
   color["Green"] = 5;
   color["Blue"] = 6;
   color["Violet"] = 7;
   color["Gray"] = 8;
   color["White"] = 9;
   while(1)//run infinitely
   {
       int total = 0;//to calculate total resistance for a resistor
       for(int i = 0; i < 4 ; i++)//to input 4 resistors
       {
           while(1)
           {
               cout<<"Enter colour to calculate resistance: ";
               string col;cin>>col;
               if(color.find(col) == color.end())//find method returns the position of col in map, end() means that the value is not present in the map
               {
                   cout<<"Enter a valid color"<<endl;
               }
               else
               {
                   total += color[col];
                   break;//valid color, so need not read again
               }
           }
       }
       cout<<"Total Resistance: "<<total<<" ohms"<<endl;
       cout<<"Enter -1 to break, any other key to continue: ";
       string ex;cin>>ex;if(ex=="-1") break;
   }
   return 0;
}

Output: