# Armstrong Number in C : Examples and Programs

## What’s Armstrong Quantity in C?

An Armstrong quantity (also referred to as a narcissistic quantity, plenary quantity, or pluperfect quantity) is a quantity that is the same as the sum of its personal digits every raised to the ability of the variety of digits. For instance, 153 is an Armstrong quantity as a result of:

It’s named after Michael F. Armstrong, who used it for instance in a programming drawback in 1969. These numbers are intriguing in arithmetic and programming as a result of they’re comparatively uncommon and infrequently utilized in workout routines to check programming expertise.

## Armstrong Quantity Instance

If the Armstrong quantity is a constructive integer of order n then it may be outlined as,

```abcde…. = pow (a, n) + pow (b, n) + pow (c, n) + pow (d, n) + pow (e, n) + ………
For instance : 0, 1, 153, 370, 371, 1634 and so on.
```

### Let’s examine whether or not 370 is an Armstrong quantity or not

```370 = (3 * 3 * 3) + (7 * 7 * 7) + (0 * 0 * 0)
Right here,
(3 * 3 * 3) = 27
(7 * 7 * 7) = 343
(0 * 0 * 0) = 0
27 + 343 + 0 = 370, which is the same as the given quantity; therefore it's an Armstrong quantity.
```

### Let’s examine 4 digits Armstrong quantity:

```1634 = (1 * 1 * 1 * 1) + (6 * 6 * 6 * 6) + (3 * 3 * 3 * 3) + (4 * 4 * 4 * 4)
Right here,
(1 * 1 * 1 * 1) = 1
(6 * 6* 6 * 6) = 1296
(3 * 3 * 3 * 3) = 81
(4 * 4 * 4 * 4) = 256
1 + 1296 + 81 + 256 = 1634, which is the same as the given quantity; therefore it's an Armstrong quantity.
```

## Algorithm of Armstrong Quantity in C

1. Take enter from the consumer
2. Initialize sum = 0 and take short-term variable to quickly retailer consumer enter (var = num)
3. Now discover out the entire variety of digits within the given quantity
4. Complete variety of digits get saved in a
5. Repeat the loop until var > 0
6. Retailer the output of whereas loop in sum
7. Examine whether or not the consumer quantity is the same as sum or not
8. Whether it is equal than print “It’s an Armstrong quantity”
9. Else print “It’s not an Armstrong quantity”

## Program of Armstrong Quantity in C

```#embrace
#embrace

int foremost ()
{
int num, var, rem, sum = 0, a = 0 ;

printf ( “ Please enter an integer: “ );  // Taking the consumer enter
scanf ( “%d”, &num );

var = num;

whereas (var != 0)	// Discovering the numbers of digits in a given quantity
{
var = var / 10;
++a;
}

var = num;

whereas (var > 0 )  	// Calculate the quantity to examine  it's Armstrong or not
{
rem = var % 10;
sum = sum +  pow( rem, a );
var = var / 10;
}

if ( sum == num )	// Examine whether or not the sum is the same as the given variety of not
{
printf ( “ %d is an Armstrong quantity n ”, num );
}
else
{
printf ( “ %d just isn't an Armstrong quantity n ”, num );
}
return 0;
}
```

### Output 1:

371 is an Armstrong quantity

### Output 2:

1045 is an Armstrong quantity

## Clarification

Within the above code, we’ve got first declared all of the variables which might be wanted in this system. The num is said to carry the consumer enter. The var is used for the short-term storage, after which rem is used to carry the rest that’s required for calculation. Eventually, we’ve got the sum and a, that are assigned to zero.

We’re accepting consumer enter after which assigning that quantity to num. Then we assign this quantity to var in order that we will make our calculation and maintain the consumer enter protected within the num variable.

Now we’re calculating the variety of digits that consumer enter has. For that, we’ve got assigned num worth to var, and we’ve got taken some time loop. The whereas loop shall be operating till (var !=0) after which divide var by ten in order that we will rely the entire variety of digits in that quantity. Since var is of integer kind, it won’t retailer a decimal quantity, after which every time, the worth of an will increase by 1. This course of is repeated till var is the same as zero. After that, it exits the loop.

Now once more, we assign num worth to var. Then we begin the loop, and this loop will run until var is bigger than zero. Now we have three steps to carry out contained in the loop. First, we discover the rest of the quantity, after which we calculate the ability of the rest utilizing pow(rem, a), the place rem represents the rest, and a represents the ability, i.e., whole variety of digits in a quantity, which was calculated above. Now we divide the var by 10, and that is accomplished as a result of we don’t require the final digit of the quantity as a result of we’ve got already used it. Since var is an integer kind, it neglects the decimal worth and shops the integer worth. This course of is repeated until var is bigger than zero; after that, it exits from the loop, and the ultimate worth is saved in sum.

As soon as the management strikes out of the loop, the if assertion checks whether or not sum is the same as the num or not, the place the num is the enter given by the consumer. If the sum is the same as num, then it’s an Armstrong quantity. Else it’s not an Armstrong quantity.

So, right here is all about “Armstrong Quantity in C.” We hope you discover this implementation informative. Keep tuned for extra upcoming blogs. Take up the Free On-line C Programming for Newcomers Course and be taught extra such ideas!