leetcode - 124. 二叉树中的最大路径和

题目：

代码：

#include 
#include 
using namespace std;

int res=INT_MIN;

typedef struct TreeNode{
	int val;
	TreeNode *left,*right;
}TreeNode,*BiTree;

void create(BiTree &T){
	int tn;
	cin>>tn;
	if(tn==-1){
		T=NULL;
		return;
	}else{
		T=new TreeNode;
		T->val=tn;
		create(T->left);
		create(T->right);
	}
}

int oneSideMax(TreeNode* root){
	if(!root){
		return 0;
	}
	int left = max(0,oneSideMax(root->left));
	int right = max(0,oneSideMax(root->right));
	res=max(res,left+right+root->val);
	return max(left,right) + root->val;
}

int maxPathSum(TreeNode* root) {
	oneSideMax(root);
	return res;
}
    
int main(){
	TreeNode* root;
	create(root);
	maxPathSum(root);
	cout<