// ------------------------------------------------------------
// A small program demonstrating how to remove every Nth element
// from a slice using clear, expressive Go patterns.
// ------------------------------------------------------------
package main
import (
"fmt"
)
/*
removeEveryNth returns a new slice with every Nth element removed.
Go slices use zero‑based indexing, so we check (index + 1) % n != 0
to keep elements that are *not* in the Nth position.
The variable "size" captures the slice length before the loop,
which avoids repeatedly accessing len(items) inside the loop.
A new slice is allocated up front with enough capacity to avoid
repeated growth operations.
*/
func removeEveryNth[T any](items []T, n int) []T {
if n <= 0 {
panic("n must be a positive integer")
}
size := len(items) // capture size once
result := make([]T, 0, size) // preallocate capacity
for i := 0; i < size; i++ {
if (i+1)%n != 0 {
result = append(result, items[i])
}
}
return result
}
/*
main demonstrates the function with a simple example.
Keeping main small and focused makes the program easy to extend.
*/
func main() {
data := make([]int, 0, 20)
for i := 1; i <= 20; i++ {
data = append(data, i) // Example slice: numbers 1–20
}
n := 3 // Remove every 3rd element
cleaned := removeEveryNth[int](data, n)
fmt.Println("Original:", data)
fmt.Println("After removing every", n, "-th element:", cleaned)
}
/*
run:
Original: [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20]
After removing every 3-th element: [1 2 4 5 7 8 10 11 13 14 16 17 19 20]
*/
