package main
import "fmt"
/*
roundUp(n, multiple)
--------------------
Rounds the integer n *up* to the nearest multiple of `multiple`.
Mathematically:
result = ceil(n / multiple) * multiple
We use integer arithmetic for efficiency:
(n + multiple - 1) / multiple → smallest integer ≥ n/m
*/
func roundUp(n int, multiple int) int {
if multiple <= 0 {
// Defensive programming: avoid undefined behavior.
// In real-world code, you'd throw or handle this differently.
return n
}
// Efficient integer rounding up:
return ((n + multiple - 1) / multiple) * multiple
}
func main() {
fmt.Println("roundUp(53, 20) =", roundUp(53, 20))
fmt.Println("roundUp(68, 30) =", roundUp(68, 30))
fmt.Println("roundUp(7, 100) =", roundUp(7, 100))
fmt.Println("roundUp(119, 100) =", roundUp(119, 100))
fmt.Println("roundUp(781, 100) =", roundUp(781, 100))
fmt.Println("roundUp(1026, 100) =", roundUp(1026, 100))
fmt.Println("roundUp(11689, 1000) =", roundUp(11689, 1000))
}
/*
run:
roundUp(53, 20) = 60
roundUp(68, 30) = 90
roundUp(7, 100) = 100
roundUp(119, 100) = 200
roundUp(781, 100) = 800
roundUp(1026, 100) = 1100
roundUp(11689, 1000) = 12000
*/
