public/subjects/reachablenumberprog.en.md

reachable_number

WARNING! VERY IMPORTANT!

For this exercise a function will be tested with the exam own main. However the student still needs to submit a structured program:

This means that:

• The package needs to be named package main.
• The submitted code needs one declared function main(func main()) even if empty.
• The function main declared needs to also pass the Restrictions Checker(illegal functions tester). It is advised for the student to just empty the function main after its own testings are done.
• Every other rules are obviously the same than for a program.

Instructions

Let us define a function f(x) by the following: first we add 1 to x, and then while the last digit of the number equals 0, we shall be deleting 0. Let us call 'y' reachable if we can apply f to x (zero or more times), and get y. 102 is reachable from 10098: f(f(f(10098))) = f(f(10099)) = f(101) = f(102). Any number is reachable from itself. You are given a positive number n, count how many integers are reachable from n.

Expected function

func Reachablenumber(n int) int {

}

Usage

Here is a possible program to test your function :

package main

import (
	"fmt"
)

func main() {
	fmt.Println(Reachablenumber(1))
	fmt.Println(Reachablenumber(10))
	fmt.Println(Reachablenumber(1001))
}

And its output :

student@ubuntu:~/[[ROOT]]/test$ go build
student@ubuntu:~/[[ROOT]]/test$ ./test
9
19
36
student@ubuntu:~/[[ROOT]]/test$