package main
import (
"fmt"
)
/*
Extracts the last N digits from a given integer.
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.
*/
func getLastNDigits(number int, digits int) int {
// Build 10^digits using integer multiplication
// Go does not have a built-in integer power function,
// so we compute it manually.
divisor := 1
for i := 0; i < digits; i++ {
divisor *= 10
}
// Modulo returns the remainder, which is exactly the last N digits
return number % divisor
}
func main() {
// Example values
number := 987654321
digits := 4
// Extract the last N digits
result := getLastNDigits(number, digits)
// Display the result
fmt.Println("Original number:", number)
fmt.Println("Digits requested:", digits)
fmt.Println("Last", digits, "digits:", result)
}
/*
run:
Original number: 987654321
Digits requested: 4
Last 4 digits: 4321
*/
