## C, , armstrong_number.c

``````// A number is called as Armstrong number if sum of cubes of digits of number is
// equal to the number itself.
// For Example 153 is an Armstrong number because 153 = 1³+5³+3³.
#include <stdio.h>

// 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
int 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
if (sum == x)
return 1;
else
return 0;
}

//
int main()
{
int x = 153;
if (isArmstrong(x) == 1)
printf("True\n");
else
printf("False\n");

x = 1253;
if (isArmstrong(x) == 1)
printf("True\n");
else
printf("False\n");

return 0;
}
``````