- btree insertion with tests

trees/btree/btree_test.go

@@ -0,0 +1,225 @@
+// Copyright (c) 2015, Emir Pasic. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package btree
+
+import (
+	_ "fmt"
+	"testing"
+)
+
+func TestBTree_search(t *testing.T) {
+	{
+		tree := NewWithIntComparator(3)
+		tree.root = &Node{entries: []*Entry{}, children: make([]*Node, 0)}
+		tests := [][]interface{}{
+			{0, 0, false},
+		}
+		for _, test := range tests {
+			index, found := tree.search(tree.root, &Entry{test[0], nil})
+			if actualValue, expectedValue := index, test[1]; actualValue != expectedValue {
+				t.Errorf("Got %v expected %v", actualValue, expectedValue)
+			}
+			if actualValue, expectedValue := found, test[2]; actualValue != expectedValue {
+				t.Errorf("Got %v expected %v", actualValue, expectedValue)
+			}
+		}
+	}
+	{
+		tree := NewWithIntComparator(3)
+		tree.root = &Node{entries: []*Entry{&Entry{2, 0}, &Entry{4, 1}, &Entry{6, 2}}, children: []*Node{}}
+		tests := [][]interface{}{
+			{0, 0, false},
+			{1, 0, false},
+			{2, 0, true},
+			{3, 1, false},
+			{4, 1, true},
+			{5, 2, false},
+			{6, 2, true},
+			{7, 3, false},
+		}
+		for _, test := range tests {
+			index, found := tree.search(tree.root, &Entry{test[0], nil})
+			if actualValue, expectedValue := index, test[1]; actualValue != expectedValue {
+				t.Errorf("Got %v expected %v", actualValue, expectedValue)
+			}
+			if actualValue, expectedValue := found, test[2]; actualValue != expectedValue {
+				t.Errorf("Got %v expected %v", actualValue, expectedValue)
+			}
+		}
+	}
+}
+
+func TestBTree_insert1(t *testing.T) {
+	// https://upload.wikimedia.org/wikipedia/commons/3/33/B_tree_insertion_example.png
+	tree := NewWithIntComparator(3)
+	assertValidTree(t, tree, 0)
+
+	tree.Put(1, 0)
+	assertValidTree(t, tree, 1)
+	assertValidTreeNode(t, tree.root, 1, 0, []int{1})
+
+	tree.Put(2, 1)
+	assertValidTree(t, tree, 2)
+	assertValidTreeNode(t, tree.root, 2, 0, []int{1, 2})
+
+	tree.Put(3, 2)
+	assertValidTree(t, tree, 3)
+	assertValidTreeNode(t, tree.root, 1, 2, []int{2})
+	assertValidTreeNode(t, tree.root.children[0], 1, 0, []int{1})
+	assertValidTreeNode(t, tree.root.children[1], 1, 0, []int{3})
+
+	tree.Put(4, 2)
+	assertValidTree(t, tree, 4)
+	assertValidTreeNode(t, tree.root, 1, 2, []int{2})
+	assertValidTreeNode(t, tree.root.children[0], 1, 0, []int{1})
+	assertValidTreeNode(t, tree.root.children[1], 2, 0, []int{3, 4})
+
+	tree.Put(5, 2)
+	assertValidTree(t, tree, 5)
+	assertValidTreeNode(t, tree.root, 2, 3, []int{2, 4})
+	assertValidTreeNode(t, tree.root.children[0], 1, 0, []int{1})
+	assertValidTreeNode(t, tree.root.children[1], 1, 0, []int{3})
+	assertValidTreeNode(t, tree.root.children[2], 1, 0, []int{5})
+
+	tree.Put(6, 2)
+	assertValidTree(t, tree, 6)
+	assertValidTreeNode(t, tree.root, 2, 3, []int{2, 4})
+	assertValidTreeNode(t, tree.root.children[0], 1, 0, []int{1})
+	assertValidTreeNode(t, tree.root.children[1], 1, 0, []int{3})
+	assertValidTreeNode(t, tree.root.children[2], 2, 0, []int{5, 6})
+
+	tree.Put(7, 2)
+	assertValidTree(t, tree, 7)
+	assertValidTreeNode(t, tree.root, 1, 2, []int{4})
+	assertValidTreeNode(t, tree.root.children[0], 1, 2, []int{2})
+	assertValidTreeNode(t, tree.root.children[1], 1, 2, []int{6})
+	assertValidTreeNode(t, tree.root.children[0].children[0], 1, 0, []int{1})
+	assertValidTreeNode(t, tree.root.children[0].children[1], 1, 0, []int{3})
+	assertValidTreeNode(t, tree.root.children[1].children[0], 1, 0, []int{5})
+	assertValidTreeNode(t, tree.root.children[1].children[1], 1, 0, []int{7})
+}
+
+func TestBTree_insert2(t *testing.T) {
+	tree := NewWithIntComparator(4)
+	assertValidTree(t, tree, 0)
+
+	tree.Put(0, 0)
+	assertValidTree(t, tree, 1)
+	assertValidTreeNode(t, tree.root, 1, 0, []int{0})
+
+	tree.Put(2, 2)
+	assertValidTree(t, tree, 2)
+	assertValidTreeNode(t, tree.root, 2, 0, []int{0, 2})
+
+	tree.Put(1, 1)
+	assertValidTree(t, tree, 3)
+	assertValidTreeNode(t, tree.root, 3, 0, []int{0, 1, 2})
+
+	tree.Put(1, 1)
+	assertValidTree(t, tree, 3)
+	assertValidTreeNode(t, tree.root, 3, 0, []int{0, 1, 2})
+
+	tree.Put(3, 3)
+	assertValidTree(t, tree, 4)
+	assertValidTreeNode(t, tree.root, 1, 2, []int{1})
+	assertValidTreeNode(t, tree.root.children[0], 1, 0, []int{0})
+	assertValidTreeNode(t, tree.root.children[1], 2, 0, []int{2, 3})
+
+	tree.Put(4, 4)
+	assertValidTree(t, tree, 5)
+	assertValidTreeNode(t, tree.root, 1, 2, []int{1})
+	assertValidTreeNode(t, tree.root.children[0], 1, 0, []int{0})
+	assertValidTreeNode(t, tree.root.children[1], 3, 0, []int{2, 3, 4})
+
+	tree.Put(5, 5)
+	assertValidTree(t, tree, 6)
+	assertValidTreeNode(t, tree.root, 2, 3, []int{1, 3})
+	assertValidTreeNode(t, tree.root.children[0], 1, 0, []int{0})
+	assertValidTreeNode(t, tree.root.children[1], 1, 0, []int{2})
+	assertValidTreeNode(t, tree.root.children[2], 2, 0, []int{4, 5})
+}
+
+func TestBTree_insert3(t *testing.T) {
+	// http://www.geeksforgeeks.org/b-tree-set-1-insert-2/
+	tree := NewWithIntComparator(6)
+	assertValidTree(t, tree, 0)
+
+	tree.Put(10, 0)
+	assertValidTree(t, tree, 1)
+	assertValidTreeNode(t, tree.root, 1, 0, []int{10})
+
+	tree.Put(20, 1)
+	assertValidTree(t, tree, 2)
+	assertValidTreeNode(t, tree.root, 2, 0, []int{10, 20})
+
+	tree.Put(30, 2)
+	assertValidTree(t, tree, 3)
+	assertValidTreeNode(t, tree.root, 3, 0, []int{10, 20, 30})
+
+	tree.Put(40, 3)
+	assertValidTree(t, tree, 4)
+	assertValidTreeNode(t, tree.root, 4, 0, []int{10, 20, 30, 40})
+
+	tree.Put(50, 4)
+	assertValidTree(t, tree, 5)
+	assertValidTreeNode(t, tree.root, 5, 0, []int{10, 20, 30, 40, 50})
+
+	tree.Put(60, 5)
+	assertValidTree(t, tree, 6)
+	assertValidTreeNode(t, tree.root, 1, 2, []int{30})
+	assertValidTreeNode(t, tree.root.children[0], 2, 0, []int{10, 20})
+	assertValidTreeNode(t, tree.root.children[1], 3, 0, []int{40, 50, 60})
+
+	tree.Put(70, 6)
+	assertValidTree(t, tree, 7)
+	assertValidTreeNode(t, tree.root, 1, 2, []int{30})
+	assertValidTreeNode(t, tree.root.children[0], 2, 0, []int{10, 20})
+	assertValidTreeNode(t, tree.root.children[1], 4, 0, []int{40, 50, 60, 70})
+
+	tree.Put(80, 7)
+	assertValidTree(t, tree, 8)
+	assertValidTreeNode(t, tree.root, 1, 2, []int{30})
+	assertValidTreeNode(t, tree.root.children[0], 2, 0, []int{10, 20})
+	assertValidTreeNode(t, tree.root.children[1], 5, 0, []int{40, 50, 60, 70, 80})
+
+	tree.Put(90, 8)
+	assertValidTree(t, tree, 9)
+	assertValidTreeNode(t, tree.root, 2, 3, []int{30, 60})
+	assertValidTreeNode(t, tree.root.children[0], 2, 0, []int{10, 20})
+	assertValidTreeNode(t, tree.root.children[1], 2, 0, []int{40, 50})
+	assertValidTreeNode(t, tree.root.children[2], 3, 0, []int{70, 80, 90})
+}
+
+func assertValidTree(t *testing.T, tree *Tree, expectedSize int) {
+	if actualValue, expectedValue := tree.size, expectedSize; actualValue != expectedValue {
+		t.Errorf("Got %v expected %v for tree size", actualValue, expectedValue)
+	}
+}
+
+func assertValidTreeNode(t *testing.T, node *Node, expectedEntries int, expectedChildren int, keys []int) {
+	if actualValue, expectedValue := len(node.entries), expectedEntries; actualValue != expectedValue {
+		t.Errorf("Got %v expected %v for entries size", actualValue, expectedValue)
+	}
+	if actualValue, expectedValue := len(node.children), expectedChildren; actualValue != expectedValue {
+		t.Errorf("Got %v expected %v for children size", actualValue, expectedValue)
+	}
+	for i, key := range keys {
+		if actualValue, expectedValue := node.entries[i].key, key; actualValue != expectedValue {
+			t.Errorf("Got %v expected %v for key", actualValue, expectedValue)
+		}
+	}
+}
+
+func BenchmarkBTree(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		tree := NewWithIntComparator(32)
+		for n := 0; n < 1000; n++ {
+			tree.Put(n, n)
+		}
+		for n := 0; n < 1000; n++ {
+			tree.Remove(n)
+		}
+	}
+}

trees/btree/main/main.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"github.com/emirpasic/gods/trees/btree"
+	"fmt"
+)
+
+func main() {
+	tree := btree.NewWithIntComparator(3)
+	tree.Put(1, 0)
+	tree.Put(2, 1)
+	tree.Put(3, 2)
+	fmt.Println()
+}