/
order.go
53 lines (47 loc) · 1.51 KB
/
order.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
// Copyright (c) 2019 Matúš Mrekaj.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License
package stacksandqueues
import (
"github.com/despire/EPI/binarytrees"
)
// OrderOfIncreasingDepth returns an array consisting of the keys at
// the same level. Keys appear in the order of the corresponding
// nodes'depths from left to right.
// Time complexity O(N).
func OrderOfIncreasingDepth(root *binarytrees.Node) [][]interface{} {
if root == nil {
return nil
}
var elemsPerLevel [][]interface{}
queue := new(queue)
// level 0
queue.Enqueue(root)
// while there are still levels to traverse.
for queue.Size() > 0 {
// traverse all nodes in the current level.
var currLevel []interface{}
for size := queue.Size(); size > 0; size-- {
curr := queue.Dequeue().(*binarytrees.Node)
currLevel = append(currLevel, curr.Data)
if curr.Left != nil {
queue.Enqueue(curr.Left)
}
if curr.Right != nil {
queue.Enqueue(curr.Right)
}
}
elemsPerLevel = append(elemsPerLevel, currLevel)
}
return elemsPerLevel
}