go/doc/progs/sort.go
2009-12-16 10:29:53 +11:00

63 lines
1.6 KiB
Go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package sort
type Interface interface {
Len() int
Less(i, j int) bool
Swap(i, j int)
}
func Sort(data Interface) {
for i := 1; i < data.Len(); i++ {
for j := i; j > 0 && data.Less(j, j-1); j-- {
data.Swap(j, j-1)
}
}
}
func IsSorted(data Interface) bool {
n := data.Len()
for i := n - 1; i > 0; i-- {
if data.Less(i, i - 1) {
return false
}
}
return true
}
// Convenience types for common cases
type IntArray []int
func (p IntArray) Len() int { return len(p) }
func (p IntArray) Less(i, j int) bool { return p[i] < p[j] }
func (p IntArray) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
type FloatArray []float
func (p FloatArray) Len() int { return len(p) }
func (p FloatArray) Less(i, j int) bool { return p[i] < p[j] }
func (p FloatArray) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
type StringArray []string
func (p StringArray) Len() int { return len(p) }
func (p StringArray) Less(i, j int) bool { return p[i] < p[j] }
func (p StringArray) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
// Convenience wrappers for common cases
func SortInts(a []int) { Sort(IntArray(a)) }
func SortFloats(a []float) { Sort(FloatArray(a)) }
func SortStrings(a []string) { Sort(StringArray(a)) }
func IntsAreSorted(a []int) bool { return IsSorted(IntArray(a)) }
func FloatsAreSorted(a []float) bool { return IsSorted(FloatArray(a)) }
func StringsAreSorted(a []string) bool { return IsSorted(StringArray(a)) }