depth_first_search.go

// c like struct
type TreeNode struct {
    Value int
    Left, Right *TreeNode // pointers
}


func DfsInOrder(treeNode *TreeNode) {
    if treeNode == nil {
        return
    }
  
    // implicit dereferencing, c's ->
    // in-order: recursive traverse left, print current node value, recursive traverse right
    DfsInOrder(treeNode.Left)
    fmt.Println(treeNode.Value)
    DfsInOrder(treeNode.Right)
}

/*
      5
     / \
    1   2
        /
       7
DFS In-Order: 1, 5, 2, 7
*/
func main() {
    // get pointers to tree struct
    tree := &TreeNode{5,
        &TreeNode{1, nil, nil},
        &TreeNode{2, &TreeNode{7, nil, nil}, nil}}

    DfsInOrder(tree)
}