/*
Extracts the last N digits from a given number.
Approach:
- To get the last N digits, compute: number % (10^digits)
- This avoids string manipulation and uses efficient arithmetic.
Parameters:
number : the original integer
digits : how many digits to extract from the end
Returns:
The last N digits as an integer.
*/
fn get_last_n_digits(number: u64, digits: u32) -> u64 {
// Compute 10^digits using u64::pow
let divisor: u64 = 10u64.pow(digits);
// Modulo returns the remainder, which is exactly the last N digits
number % divisor
}
fn main() {
// Example values
let number: u64 = 987_654_321;
let digits: u32 = 4;
// Extract the last N digits
let result: u64 = get_last_n_digits(number, digits);
// Display the result
println!("Original number: {}", number);
println!("Digits requested: {}", digits);
println!("Last {} digits: {}", digits, result);
}
/*
run:
Original number: 987654321
Digits requested: 4
Last 4 digits: 4321
*/
