public/subjects/logic_number

logic_number

Instructions

In this exercise it will be given an example of a sequence of numbers.

Your purpose is to determinate if the sequence returns true or false. For this you have to create a function number_logic that will take a number u32 and return true if the number is the sum of its own digits, each raised to the power of the number of digits, and false otherwise.

Example:

• 9 returns true, because 9 = 9^1 = 9
• 10 returns false, because 10 != 1^2 + 0^2 = 1
• 153 returns true, because: 153 = 1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153
• 154 returns false, because: 154 != 1^3 + 5^3 + 4^3 = 1 + 125 + 64 = 190

Notions

• https://doc.rust-lang.org/book/ch18-00-patterns.html

Expected functions

pub fn number_logic(num: u32) -> bool {}

Usage

Here is a program to test your function.

use logic_number::logic_number;

fn main() {
    let array = [9, 10, 153, 154];
    for pat in &array {
        if number_logic(*pat) == true {
            println!(
                "this number returns {} because the number {} obey the rules of the sequence",
                number_logic(*pat),
                pat
            )
        }
        if number_logic(*pat) == false {
            println!("this number returns {} because the number {} does not obey the rules of the sequence", number_logic(*pat),pat )
        }
    }
}

And its output

student@ubuntu:~/[[ROOT]]/test$ cargo run
this number returns true because the number 9 obey the rules of the sequence
this number returns false because the number 10 does not obey the rules of the sequence
this number returns true because the number 153 obey the rules of the sequence
this number returns false because the number 154 does not obey the rules of the sequence
student@ubuntu:~/[[ROOT]]/test$