armstrong_number_templated.cpp

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#include <cassert>   
#include <cmath>     
#include <iostream>  
 
namespace dynamic_programming {
 
template <typename T>
bool is_armstrong(const T &number) {
    int count = 0, temp = number, result = 0, rem = 0;
 
    // Count the number of digits of the given number.
    // For example: 153 would be 3 digits.
    while (temp != 0) {
        temp /= 10;
        count++;
    }
 
    // Calculation for checking of armstrongs number i.e.
    // in an n-digit number sum of the digits is raised to a power of `n` is
    // equal to the original number.
    temp = number;
    while (temp != 0) {
        rem = temp % 10;
        result += static_cast<T>(std::pow(rem, count));
        temp /= 10;
    }
 
    if (result == number) {
        return true;
    } else {
        return false;
    }
}
}  // namespace dynamic_programming
 
static void tests() {
    assert(dynamic_programming::is_armstrong(153) == true);
    assert(dynamic_programming::is_armstrong(1) == true);
    assert(dynamic_programming::is_armstrong(0) == true);
    assert(dynamic_programming::is_armstrong(370) == true);
    assert(dynamic_programming::is_armstrong(1634) == true);
    assert(dynamic_programming::is_armstrong(580) == false);
    assert(dynamic_programming::is_armstrong(15) == false);
    assert(dynamic_programming::is_armstrong(1024) == false);
    assert(dynamic_programming::is_armstrong(989) == false);
    assert(dynamic_programming::is_armstrong(103) == false);
 
    std::cout << "All tests have successfully passed!\n";
}
 
int main() {
    tests();  // run self-test implementations
    return 0;
}