C++ Class Template Specialization in C++ | HackerRank Solution

Hello coders, today we are going to solve C++ Class Template Specialization HackerRank Solution in C++.

C++ Class Template Specialization


You are given a main function which reads the enumeration values for two different types as input, then prints out the corresponding enumeration names. Write a class template that can provide the names of the enumeration values for both types. If the enumeration value is not valid, then print unknown.

Input Format

The first line contains t, the number of test cases.
Each of the t subsequent lines contains two space-separated integers. The first integer is a color value, c, and the second integer is a fruit value, f.


  • 1 <= t <= 100
  • – 2 x 109 <= c <= 2 x 109
  • – 2 x 109 <= f <= 2 x 109

Output Format

The locked stub code in your editor prints t lines containing the color name and the fruit name corresponding to the input enumeration index.

Sample Input

1 0
3 3

Sample Output

green apple
unknown unknown


Since t = 2, there are two lines of output.

  1. The two input index values, 1 and 0, correspond to green in the color enumeration and apple in the fruit enumeration. Thus, we print green apple.
  2. The two input values, 3 and 3, are outside of the range of our enums. Thus, we print unknown unknown.

Solution – C++ Class Template Specialization in C++


#include <iostream>
using namespace std;
enum class Fruit { apple, orange, pear };
enum class Color { red, green, orange };

template <typename T> struct Traits;

// Define specializations for the Traits class template here.
template <> 
struct Traits<Fruit>{
    static string name(int index){
                case 0:return "apple";
                case 1: return "orange" ;
                case 2: return "pear";
        return "unknown";
template <> 
struct Traits<Color>{
    static string name(int index){
                case 0:return "red";
                case 1: return "green" ;
                case 2: return "orange";           
        return "unknown";  

int main()
	int t = 0; std::cin >> t;

    for (int i=0; i!=t; ++i) {
        int index1; std::cin >> index1;
        int index2; std::cin >> index2;
        cout << Traits<Color>::name(index1) << " ";
        cout << Traits<Fruit>::name(index2) << "\n";

Disclaimer: The above Problem (C++ Class Template Specialization) is generated by Hacker Rank but the Solution is Provided by CodingBroz. This tutorial is only for Educational and Learning Purpose.

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