tests/cut_the_tree/dll/dll_test.go

97 lines
2.2 KiB
Go

package dll
import (
"testing"
"github.com/stretchr/testify/require"
)
func TestList(t *testing.T) {
t.Run("empty list", func(t *testing.T) {
l := NewList()
require.Equal(t, l.Len(), 0)
require.Nil(t, l.Front())
require.Nil(t, l.Back())
})
t.Run("complex", func(t *testing.T) {
l := NewList()
l.PushFront(10)
require.Equal(t, []int{10}, transpond(l))
require.Equal(t, 1, l.Len())
l.Remove(l.Front())
require.Equal(t, []int{}, transpond(l))
require.Equal(t, 0, l.Len())
l.PushFront(10)
require.Equal(t, []int{10}, transpond(l))
require.Equal(t, 1, l.Len())
l.PushBack(20)
require.Equal(t, []int{20, 10}, transpond(l))
require.Equal(t, 2, l.Len())
l.PushBack(30)
require.Equal(t, []int{30, 20, 10}, transpond(l))
require.Equal(t, 3, l.Len())
middle := l.Back().Next // 20
l.Remove(middle)
require.Equal(t, []int{30, 10}, transpond(l))
require.Equal(t, 2, l.Len())
l.PushFront(20)
require.Equal(t, []int{30, 10, 20}, transpond(l))
require.Equal(t, 3, l.Len())
l.Remove(l.Back())
require.Equal(t, []int{10, 20}, transpond(l))
require.Equal(t, 2, l.Len())
l.PushBack(30)
require.Equal(t, []int{30, 10, 20}, transpond(l))
require.Equal(t, 3, l.Len())
l.Remove(l.Front())
require.Equal(t, []int{30, 10}, transpond(l))
require.Equal(t, 2, l.Len())
l.PushFront(20)
require.Equal(t, []int{30, 10, 20}, transpond(l))
require.Equal(t, 3, l.Len())
for i, v := range [...]int{40, 50, 60, 70, 80} {
if i%2 == 0 {
l.PushFront(v)
} else {
l.PushBack(v)
}
}
require.Equal(t, []int{70, 50, 30, 10, 20, 40, 60, 80}, transpond(l))
require.Equal(t, 8, l.Len())
l.MoveToFront(l.Front())
require.Equal(t, []int{70, 50, 30, 10, 20, 40, 60, 80}, transpond(l))
require.Equal(t, 8, l.Len())
l.MoveToFront(l.Back().Next.Next) // 30
require.Equal(t, []int{70, 50, 10, 20, 40, 60, 80, 30}, transpond(l))
require.Equal(t, 8, l.Len())
l.MoveToFront(l.Back())
require.Equal(t, []int{50, 10, 20, 40, 60, 80, 30, 70}, transpond(l))
require.Equal(t, 8, l.Len())
})
}
func transpond(l *List) []int {
elems := make([]int, 0, l.Len())
for i := l.Back(); i != nil; i = i.Next {
elems = append(elems, i.Value.(int))
}
return elems
}