8642. Four digit Armstrong numbers

A four-digit number is called an Armstrong number if the sum of the fourth powers of its digits equals the number itself.

For example: 8208 = 8⁴ + 2⁴  + 0⁴ + 8⁴, therefore, 8208 is an Armstrong number.

Print all Armstrong numbers in the range from a to b.

Input. Two integers a and b (1000 ≤ a ≤ b ≤ 9999).

Output. Print all Armstrong numbers in a single line in the range from a to b.

Sample input	Sample output
1000 3000	1634

SOLUTION

loops

Algorithm analysis

Let’s iterate through the numbers from a to b. For each number i = (a ≤ i ≤ b) extract the digits of thousands x, hundreds y, tens z, and ones u. If the number i is an Armstrong number (i = x⁴ + y⁴ + z⁴ + u⁴), print it.

Algorithm implementation

Read the input data.

scanf("%d %d", &a, &b);

Iterate through the numbers from a to b.

for (i = a; i <= b; i++)

{

Extract the digits of the number i = .

x = a / 1000;

y = i / 100 % 10;

z = i / 10 % 10;

u = i % 10;

If the number i is an Armstrong number (i = x⁴ + y⁴ + z⁴ + u⁴), print it.

if (x * x * x * x + y * y * y * y + z * z * z * z +

u * u * u * u == i) printf("%d ", i);

}

printf("\n");

Python implementation

Read the input data.

a, b = map(int, input().split())

Iterate through the numbers from a to b.

for i in range(a, b + 1):

Extract the digits of the number i = .

x = i // 1000

y = (i // 100) % 10

z = (i // 10) % 10

u = i % 10

If the number i is an Armstrong number (i = x⁴ + y⁴ + z⁴ + u⁴), print it.

if x**4 + y**4 + z**4 + u**4 == i:

print(i, end=" ")

print()