Program To Check Armstrong Number

// C++ program to determine whether
// the number is Armstrong number
// or not
#include <bits/stdc++.h>
using namespace std;

// Function to calculate x
// raised to the power y
int power(int x, unsigned int y)
{
	if (y == 0)
		return 1;
	if (y % 2 == 0)
		return (power(x, y / 2) * power(x, y / 2));

	return (x * power(x, y / 2) * power(x, y / 2));
}

// Function to calculate
// order of the number
int order(int x)
{
	int n = 0;
	while (x) {
		n++;
		x = x / 10;
	}
	return n;
}

// Function to check whether the
// given number is Armstrong number
// or not
bool isArmstrong(int x)
{
	// Calling order function
	int n = order(x);
	int temp = x, sum = 0;

	while (temp) {
		int r = temp % 10;
		sum += power(r, n);
		temp = temp / 10;
	}

	// If satisfies Armstrong
	// condition
	return (sum == x);
}

// Driver code
int main()
{
	int x = 153;
	cout << boolalpha << isArmstrong(x) << endl;

	x = 1253;
	cout << boolalpha << isArmstrong(x) << endl;

	return 0;
}