Skip to content
Permalink
Branch: master
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
61 lines (52 sloc) 1.09 KB
// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
// See page 86.
// Rev reverses a slice.
package main
import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
)
func main() {
//!+array
a := [...]int{0, 1, 2, 3, 4, 5}
reverse(a[:])
fmt.Println(a) // "[5 4 3 2 1 0]"
//!-array
//!+slice
s := []int{0, 1, 2, 3, 4, 5}
// Rotate s left by two positions.
reverse(s[:2])
reverse(s[2:])
reverse(s)
fmt.Println(s) // "[2 3 4 5 0 1]"
//!-slice
// Interactive test of reverse.
input := bufio.NewScanner(os.Stdin)
outer:
for input.Scan() {
var ints []int
for _, s := range strings.Fields(input.Text()) {
x, err := strconv.ParseInt(s, 10, 64)
if err != nil {
fmt.Fprintln(os.Stderr, err)
continue outer
}
ints = append(ints, int(x))
}
reverse(ints)
fmt.Printf("%v\n", ints)
}
// NOTE: ignoring potential errors from input.Err()
}
//!+rev
// reverse reverses a slice of ints in place.
func reverse(s []int) {
for i, j := 0, len(s)-1; i < j; i, j = i+1, j-1 {
s[i], s[j] = s[j], s[i]
}
}
//!-rev
You can’t perform that action at this time.