46 lines
908 B
Go
46 lines
908 B
Go
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package main
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type TreeNode struct {
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Val int
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Left *TreeNode
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Right *TreeNode
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}
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/**
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* Definition for a binary tree node.
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* type TreeNode struct {
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* Val int
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* Left *TreeNode
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* Right *TreeNode
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* }
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*/
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func rightSideView(root *TreeNode) (out []int) {
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if root == nil {
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return
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}
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for stack := []*TreeNode{root}; len(stack) != 0; {
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top := stack[len(stack)-1]
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if len(stack) > len(out) {
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out = append(out, top.Val)
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}
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if top.Right != nil {
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stack = append(stack, top.Right)
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} else if top.Left != nil {
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stack = append(stack, top.Left)
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} else {
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stack = stack[:len(stack)-1]
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if len(stack) != 0 {
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new_top := stack[len(stack)-1]
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// Easiest way to DFS by modification of tree.
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// There was no requirement to keep it intact ¯\_(ツ)_/¯.
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if new_top.Right == top {
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new_top.Right = nil
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} else {
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new_top.Left = nil
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}
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}
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}
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}
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return
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}
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