怎样分析python二叉树的最大路径和

/** * Definition for a binary tree node. * type TreeNode struct { *     Val int *     Left *TreeNode *     Right *TreeNode * } */func maxPathSum(root *TreeNode) int {    if root==nil{        return 0    }    if root.Left!=nil && root.Right!=nil{    lr:=maxPathSumRoot(root.Left)    rr:=maxPathSumRoot(root.Right)    l:=maxPathSum(root.Left)    r:=maxPathSum(root.Right)    a:=[]int{root.Val,root.Val+lr,root.Val+rr,lr,rr,root.Val+lr+rr,l,r}         return max(a)    }else if root.Left!=nil {         lr:=maxPathSumRoot(root.Left)          l:=maxPathSum(root.Left)         a:=[]int{root.Val,root.Val+lr,lr,l}         return max(a)    }else if root.Right!=nil{          rr:=maxPathSumRoot(root.Right)         r:=maxPathSum(root.Right)         a:=[]int{root.Val,root.Val+rr,rr,r}         return max(a)    }        return root.Val
}
func max(arr []int)  int{    max:=-1<<31    for i:=0;i        if max            max=arr[i]        }    }    return max}
func maxPathSumRoot(root *TreeNode) int {    if root==nil{        return 0    }       l:=maxPathSumRoot(root.Left)    r:=maxPathSumRoot(root.Right)    return max([]int{l+root.Val,r+root.Val,root.Val}) }