Tree is a collection of tree nodes. Each tree node has a value, a left pointer point to left node and a right pointer point to right node.
import (
tree "github.com/duke-git/lancet/v2/datastructure/tree"
)
- NewBSTree
- Insert
- Delete
- PreOrderTraverse
- InOrderTraverse
- PostOrderTraverse
- LevelOrderTraverse
- Depth
- HasSubTree
BSTree is a binary search tree data structure in which each node has at two children, which are referred to as the left child and the right child. In BSTree: leftNode < rootNode < rightNode. Type T should implements Compare function in constraints.Comparator interface.
Make a BSTree pointer instance
Signature:
func NewBSTree[T any](rootData T, comparator constraints.Comparator) *BSTree[T]
type BSTree[T any] struct {
root *datastructure.TreeNode[T]
comparator constraints.Comparator
}
type TreeNode[T any] struct {
Value T
Left *TreeNode[T]
Right *TreeNode[T]
}
Example:
package main
import (
"fmt"
tree "github.com/duke-git/lancet/v2/datastructure/tree"
)
type intComparator struct{}
func (c *intComparator) Compare(v1, v2 any) int {
val1, _ := v1.(int)
val2, _ := v2.(int)
if val1 < val2 {
return -1
} else if val1 > val2 {
return 1
}
return 0
}
func main() {
bstree := tree.NewBSTree(6, &intComparator{})
fmt.Println(bstree) //
}
Insert value into binary search tree
Signature:
func (t *BSTree[T]) Insert(data T)
Example:
package main
import (
"fmt"
tree "github.com/duke-git/lancet/v2/datastructure/tree"
)
type intComparator struct{}
func (c *intComparator) Compare(v1, v2 any) int {
val1, _ := v1.(int)
val2, _ := v2.(int)
if val1 < val2 {
return -1
} else if val1 > val2 {
return 1
}
return 0
}
func main() {
bstree := tree.NewBSTree(6, &intComparator{})
bstree.Insert(7)
bstree.Insert(5)
bstree.Insert(2)
bstree.Insert(4)
fmt.Println(bstree.PreOrderTraverse()) //6, 5, 2, 4, 7
}
Delete value of binary search tree
Signature:
func (t *BSTree[T]) Delete(data T)
Example:
package main
import (
"fmt"
tree "github.com/duke-git/lancet/v2/datastructure/tree"
)
type intComparator struct{}
func (c *intComparator) Compare(v1, v2 any) int {
val1, _ := v1.(int)
val2, _ := v2.(int)
if val1 < val2 {
return -1
} else if val1 > val2 {
return 1
}
return 0
}
func main() {
bstree := tree.NewBSTree(6, &intComparator{})
bstree.Insert(7)
bstree.Insert(5)
bstree.Insert(2)
bstree.Insert(4)
bstree.Delete(4)
fmt.Println(bstree.PreOrderTraverse()) //2, 5, 6, 7
}
Traverse tree nodes in pre order
Signature:
func (t *BSTree[T]) PreOrderTraverse() []T
Example:
package main
import (
"fmt"
tree "github.com/duke-git/lancet/v2/datastructure/tree"
)
type intComparator struct{}
func (c *intComparator) Compare(v1, v2 any) int {
val1, _ := v1.(int)
val2, _ := v2.(int)
if val1 < val2 {
return -1
} else if val1 > val2 {
return 1
}
return 0
}
func main() {
bstree := tree.NewBSTree(6, &intComparator{})
bstree.Insert(7)
bstree.Insert(5)
bstree.Insert(2)
bstree.Insert(4)
fmt.Println(bstree.PreOrderTraverse()) //6, 5, 2, 4, 7
}
Traverse tree nodes in middle order
Signature:
func (t *BSTree[T]) InOrderTraverse() []T
Example:
package main
import (
"fmt"
tree "github.com/duke-git/lancet/v2/datastructure/tree"
)
type intComparator struct{}
func (c *intComparator) Compare(v1, v2 any) int {
val1, _ := v1.(int)
val2, _ := v2.(int)
if val1 < val2 {
return -1
} else if val1 > val2 {
return 1
}
return 0
}
func main() {
bstree := tree.NewBSTree(6, &intComparator{})
bstree.Insert(7)
bstree.Insert(5)
bstree.Insert(2)
bstree.Insert(4)
fmt.Println(bstree.InOrderTraverse()) //2, 4, 5, 6, 7
}
Traverse tree nodes in post order
Signature:
func (t *BSTree[T]) PostOrderTraverse() []T
Example:
package main
import (
"fmt"
tree "github.com/duke-git/lancet/v2/datastructure/tree"
)
type intComparator struct{}
func (c *intComparator) Compare(v1, v2 any) int {
val1, _ := v1.(int)
val2, _ := v2.(int)
if val1 < val2 {
return -1
} else if val1 > val2 {
return 1
}
return 0
}
func main() {
bstree := tree.NewBSTree(6, &intComparator{})
bstree.Insert(7)
bstree.Insert(5)
bstree.Insert(2)
bstree.Insert(4)
fmt.Println(bstree.PostOrderTraverse()) //5, 2, 4, 7, 6
}
Traverse tree nodes in node level order
Signature:
func (t *BSTree[T]) LevelOrderTraverse() []T
Example:
package main
import (
"fmt"
tree "github.com/duke-git/lancet/v2/datastructure/tree"
)
type intComparator struct{}
func (c *intComparator) Compare(v1, v2 any) int {
val1, _ := v1.(int)
val2, _ := v2.(int)
if val1 < val2 {
return -1
} else if val1 > val2 {
return 1
}
return 0
}
func main() {
bstree := tree.NewBSTree(6, &intComparator{})
bstree.Insert(7)
bstree.Insert(5)
bstree.Insert(2)
bstree.Insert(4)
fmt.Println(bstree.LevelOrderTraverse()) //6, 5, 7, 2, 4
}
Get the depth of a binary saerch tree
Signature:
func (t *BSTree[T]) Depth() int
Example:
package main
import (
"fmt"
tree "github.com/duke-git/lancet/v2/datastructure/tree"
)
type intComparator struct{}
func (c *intComparator) Compare(v1, v2 any) int {
val1, _ := v1.(int)
val2, _ := v2.(int)
if val1 < val2 {
return -1
} else if val1 > val2 {
return 1
}
return 0
}
func main() {
bstree := tree.NewBSTree(6, &intComparator{})
bstree.Insert(7)
bstree.Insert(5)
bstree.Insert(2)
bstree.Insert(4)
fmt.Println(bstree.Depth()) //4
}
Check if the given tree is sub tree of origin tree or not
Signature:
func (t *BSTree[T]) HasSubTree(subTree *BSTree[T]) bool
Example:
package main
import (
"fmt"
tree "github.com/duke-git/lancet/v2/datastructure/tree"
)
type intComparator struct{}
func (c *intComparator) Compare(v1, v2 any) int {
val1, _ := v1.(int)
val2, _ := v2.(int)
if val1 < val2 {
return -1
} else if val1 > val2 {
return 1
}
return 0
}
func main() {
superTree := tree.NewBSTree(8, &intComparator{})
superTree.Insert(4)
superTree.Insert(5)
superTree.Insert(6)
superTree.Insert(9)
superTree.Insert(4)
subTree := tree.NewBSTree(5, &intComparator{})
subTree.Insert(4)
subTree.Insert(6)
fmt.Println(superTree.HasSubTree(subTree)) //true
fmt.Println(subTree.HasSubTree(superTree)) //false
}
Print the structure of binary saerch tree
Signature:
func (t *BSTree[T]) Print()
Example:
package main
import (
"fmt"
tree "github.com/duke-git/lancet/v2/datastructure/tree"
)
type intComparator struct{}
func (c *intComparator) Compare(v1, v2 any) int {
val1, _ := v1.(int)
val2, _ := v2.(int)
if val1 < val2 {
return -1
} else if val1 > val2 {
return 1
}
return 0
}
func main() {
bstree := tree.NewBSTree(6, &intComparator{})
bstree.Insert(7)
bstree.Insert(5)
bstree.Insert(2)
bstree.Insert(4)
fmt.Println(bstree.Print())
// 6
// / \
// / \
// / \
// / \
// 5 7
// /
// /
// 2
// \
// 4
}